Slavery in the United States began soon after English colonists first settled Virginia in 1607 and lasted as a legal institution until the passage of the Thirteenth Amendment to the United States Constitution in 1865.
Before the widespread establishment of chattel slavery, much labor was organized under a system of bonded labor known as indentured servitude. This typically lasted for several years for white and black alike, and it was a means of using labor to pay the costs of transporting people to the colonies. By the 18th century, court rulings established the racial basis of the American incarnation of slavery to apply chiefly to Black Africans and people of African descent, and occasionally to Native Americans. A 1705 Virginia law stated slavery would apply to those peoples from nations that were not Christian. In part because of the success of tobacco as a cash crop in the Southern colonies, its labor-intensive character caused planters to import more slaves for labor by the end of the 17th century than did the northern colonies. The South had a significantly higher number and proportion of slaves in the population. Religious differences contributed to this geographic disparity as well.
From 1654 until 1865, slavery for life was legal within the boundaries of much of the present United States. Most slaves were black and were held by whites, although some Native Americans and free blacks also held slaves; there were a small number of white slaves as well. The majority of slaveholding was in the southern United States where most slaves were engaged in an efficient machine-like gang system of agriculture. According to the 1860 U.S. census, nearly four million slaves were held in a total population of just over 12 million in the 15 states in which slavery was legal. Of all 8,289,782 free persons in the 15 slave states, 393,967 people (4.8%) held slaves, with the average number of slaves held by any single owner being 10.  The majority of slaves were held by planters, defined by historians as those who held 20 or more slaves. Ninety-five percent of black people lived in the South, comprising one-third of the population there, as opposed to 2% of the population of the North. The wealth of the United States in the first half of the 19th century was greatly enhanced by the labor of African Americans. 
But with the Union victory in the American Civil War, the slave-labor system was abolished in the South. This contributed to the decline of the postbellum Southern economy, but it was most affected by the continuing decline in the price of cotton through the end of the century. That made it difficult for the region to recover from the war, as did its comparative lack of infrastructure, which kept products from markets. The South faced significant new competition from foreign cotton producers such as India and Egypt. Northern industry, which had expanded rapidly before and during the war, surged even further ahead of the South's agricultural economy. Industrialists from northeastern states came to dominate many aspects of the nation's life, including social and some aspects of political affairs. The planter class of the South lost power temporarily. The rapid economic development following the Civil War accelerated the development of the modern U.S. industrial economy.
Twelve million Africans were shipped to the Americas from the 16th to the 19th centuries.  Of these, an estimated 645,000 were brought to what is now the United States. The largest number were shipped to Brazil. The slave population in the United States had grown to four million by the 1860 Census.
The United States is unique in that it was the last Western country to free all of its slaves (at the end of the Civil War in 1865).
See main article: Slavery in Colonial United States. The first record of African slavery in Colonial America occurred in 1619. A Dutch ship, the White Lion, had captured 20 enslaved Africans in a battle with a Spanish ship bound for Mexico. The Dutch ship had been damaged first by the battle and then more severely in a great storm during the late summer when it came ashore at Old Point Comfort, site of present day Fort Monroe in Virginia. Though the colony was in the middle of a period later known as "The Great Migration" (1618-1623), during which its population grew from 450 to 4,000 residents, extremely high mortality rates from disease, malnutrition, and war with Native Americans kept the population of able-bodied laborers low http://www.virtualjamestown.org/timeline2.html. With the Dutch ship being in severe need of repairs and supplies and the colonists being in need of able-bodied workers, the human cargo was traded for food and services.
In addition to African slaves, Europeans, mostly Irish, Scottish, English, and Germans, were brought over in substantial numbers as indentured servants, particularly in the British Thirteen Colonies. Over half of all white immigrants to the English colonies of North America during the 17th and 18th centuries may have been indentured servants. In the 18th century numerous Europeans traveled to the colonies as redemptioners. The white citizens of Virginia, who had arrived from Britain, decided to treat the first Africans in Virginia as indentured servants. As with European indentured servants, the Africans were freed after a stated period and given the use of land and supplies by their former owners. At least one African American from this period, Anthony Johnson, became a landowner on the Eastern Shore and a slave-owner. The major problem with indentured servants was that, in time, they would be freed, but they were unlikely to become prosperous. The best lands in the tidewater regions were already in the hands of wealthy plantation families by 1650, and the former servants became an underclass. Bacon's Rebellion showed that the poor laborers and farmers could prove a dangerous element to the wealthy landowners. By switching to pure chattel slavery, new white laborers and small farmers were mostly limited to those who could afford to immigrate and support themselves. In addition, improving economic conditions in England meant that fewer laborers wanted to migrate to the colonies as indentured servants, so the planters needed to find new sources of labor.
The transformation from indentured servitude to racial slavery happened gradually. There were no laws regarding slavery early in Virginia's history. However, by 1640, the Virginia courts had sentenced at least one black servant to slavery.
In 1654, John Casor, a black man, became the first legally recognized slave in the area that became the United States. A court in Northampton County ruled against Casor, declaring him property for life, "owned" by the black colonist Anthony Johnson. Since persons with African origins were not English citizens by birth, they were not necessarily covered by English Common Law. Elizabeth Key Grinstead successfully gained her freedom in the Virginia courts in the 1650's by making her case as the daughter of a free Englishman Thomas Key and his negro slave.
Shortly after the Elizabeth Key trial, in 1662 Virginia passed a law on partus, stating that any children of enslaved mothers would follow her status and automatically be slaves, no matter if the father was a freeborn Englishman. The Virginia Slave codes of 1705 defined as slaves those people imported from nations that were not Christian, as well as Indians which were sold to colonists by other American Indians. During the British colonial period, every colony had slavery. Those in the north were primarily house servants. Early on, slaves in the South worked on farms and plantations growing indigo, rice, and tobacco; cotton became a major crop after the 1790s. In South Carolina in 1720 about 65% of the population consisted of slaves. Slaves were used by rich farmers and plantation owners with commercial export operations. Backwoods subsistence farmers seldom owned slaves.
Some of the British colonies attempted to abolish the international slave trade, fearing that the importation of new Africans would be disruptive. Virginia bills to that effect were vetoed by the British Privy Council; Rhode Island forbade the import of slaves in 1774. All of the colonies except Georgia had banned or limited the African slave trade by 1786; Georgia did so in 1798 - although some of these laws were later repealed.
The British West Africa Squadron's slave trade suppression activities were assisted by forces from the United States Navy, starting in 1820 with the USS Cyane. Initially, this consisted of a few ships. With the Webster-Ashburton Treaty of 1842, the relationship was formalised and they jointly ran the Africa Squadron.
As the nation expanded west, so did the cultivation of cotton and the institution of slavery. Historian Peter Kolchin wrote, "By breaking up existing families and forcing slaves to relocate far from everyone and everything they knew" this migration "replicated (if on a reduced level) many of [the] horrors" of the Atlantic slave trade. Historian Ira Berlin called this forced migration the Second Middle Passage. Characterizing it as the "central event” in the life of a slave between the American Revolution and the Civil War, Berlin wrote that whether they were uprooted themselves or simply lived in fear that they or their families would be involuntarily moved, "the massive deportation traumatized black people, both slave and free."
Although complete statistics are lacking, it is estimated that 1,000,000 slaves moved west from the Old South between 1790 and 1860. Most of the slaves were moved from Maryland, Virginia, and the Carolinas. Originally the points of destination were Kentucky and Tennessee, but after 1810 the states of the Deep South: Georgia, Alabama, Mississippi, Louisiana and Texas received the most. This corresponded to the massive expansion of cotton cultivation in that region, which needed labor. In the 1830s, almost 300,000 were transported, with Alabama and Mississippi receiving 100,000 each. Every decade between 1810 and 1860 had at least 100,000 slaves moved from their state of origin. In the final decade before the Civil War, 250,000 were moved. Michael Tadman, in a 1989 book Speculators and Slaves: Masters, Traders, and Slaves in the Old South, indicates that 60-70% of interregional migrations were the result of the sale of slaves. In 1820 a child in the Upper South had a 30% chance to be sold south by 1860.
Slave traders were responsible for the majority of the slaves that moved west. Only a minority moved with their families and existing owner. Slave traders had little interest in purchasing or transporting intact slave families, although in the interest of creating a "self-reproducing labor force", equal numbers of men and women were transported. Berlin wrote, "The internal slave trade became the largest enterprise in the South outside the plantation itself, and probably the most advanced in its employment of modern transportation, finance, and publicity." The slave trade industry developed its own unique language with terms such as "prime hands, bucks, breeding wenches, and fancy girls" coming into common use. The expansion of the interstate slave trade contributed to the "economic revival of once depressed seaboard states" as demand accelerated the value of the slaves who were subject to sale.
Some traders moved their "chattels" by sea, with Norfolk to New Orleans being the most common route, but most slaves were forced to walk. Regular migration routes were established and were served by a network of slave pens, yards, and warehouses needed as temporary housing for the slaves. As the trek advanced, some slaves were sold and new ones purchased. Berlin concluded, "In all, the slave trade, with its hubs and regional centers, its spurs and circuits, reached into every cranny of southern society. Few southerners, black or white, were untouched."
The death rate for the slaves on their way to their new destination across the American South was much less than that of the captives across the Atlantic Ocean. Mortality was still higher than the normal death rate. Berlin summarizes the experience:
Once the trip was ended, slaves faced a life on the frontier significantly different from their experiences back east. Clearing trees and starting crops on virgin fields was harsh and backbreaking work. A combination of inadequate nutrition, bad water, and exhaustion from both the journey and the work weakened the newly arrived slaves and produced casualties. The preferred locations of the new plantations at rivers' edges, with mosquitoes and other environmental challenges, threatened the survival of slaves. They had acquired only limited immunities in their previous homes. The death rate was such that, in the first few years of hewing a plantation out of the wilderness, some planters preferred whenever possible to use rented slaves rather than their own.
The harsh conditions on the frontier increased slave resistance and led to much more reliance on violence by the owners and overseers. Many of the slaves were new to cotton fields and unaccustomed to the "sunrise-to-sunset gang labor" required by their new life. Slaves were driven much harder than when they were involved in growing tobacco or wheat back east. Slaves also had less time and opportunity to boost the quality of their lifestyle by raising their own livestock or tending vegetable gardens, for either their own consumption or trade, as they could in the eastern south.
In Louisiana it was sugar, rather than cotton, that was the main crop. Between 1810 and 1830 the number of slaves increased from under 10,000 to over 42,000. New Orleans became nationally important as a slave port and by the 1840s had the largest slave market in the country. Dealing with sugar cane was even more physically demanding than growing cotton. Planters preferred young males, who represented two-thirds of the slave purchases. The largely young, unmarried male slave force made the reliance on violence by the owners “especially savage.”
Historian Kenneth M. Stampp describes the role of coercion in slavery, “Without the power to punish, which the state conferred upon the master, bondage could not have existed. By comparison, all other techniques of control were of secondary importance.” Stampp further notes that while rewards sometimes led slaves to perform adequately, most agreed with an Arkansas slaveholder, who wrote:
According to both the Pulitzer Prize-winning historian David Brion Davis and Marxist historian Eugene Genovese, treatment of slaves was both harsh and inhumane. Whether laboring or walking about in public, people living as slaves were regulated by legally authorized violence. Davis makes the point that, while some aspects of slavery took on a "welfare capitalist" look,:
On large plantations, slave overseers were authorized to whip and brutalize non-compliant slaves. According to an account by a plantation overseer to a visitor, "'some negroes are determined never to let a white man whip them and will resist you, when you attempt it; of course you must kill them in that case"  Laws were passed that fined owners for not punishing recaptured runaway slaves. Slave codes authorized, indemnified or even required the use of violence, and were denounced by abolitionists for their brutality. Both slaves and free blacks were regulated by the Black Codes and had their movements monitored by slave patrols conscripted from the white population which were allowed to use summary punishment against escapees, sometimes maiming or killing them. In addition to physical abuse and murder, slaves were at constant risk of losing members of their families if their owners decided to trade them for profit, punishment, or to pay debts. A few slaves retaliated by murdering owners and overseers, burning barns, killing horses, or staging work slowdowns. Stampp, without contesting Genovese's assertions concerning the violence and sexual exploitation faced by slaves, does question the appropriateness of a Marxian approach in analyzing the owner-slave relationship.
Genovese claims that because the slaves were the legal property of their owners, it was not unusual for enslaved black women to be raped by their owners, members of their owner's families, or their owner's friends. Children who resulted from such rapes were slaves as well because they took the status of their mothers, unless freed by the slaveholder. Nell Irwin Painter and other historians have also documented that Southern history went "across the color line". Contemporary accounts by Mary Chesnut and Fanny Kemble, both married in the planter class, as well as accounts by former slaves gathered under the Works Progress Administration (WPA), all attested to the abuse of women slaves by white men of the owning and overseer class.
However, the Nobel economist Robert Fogel controversially describes the belief that slave-breeding and sexual exploitation destroyed the black family as a myth. He argues that the family was the basic unit of social organization under slavery; it was to the economic interest of planters to encourage the stability of slave families, and most of them did so. Most slave sales were either of whole families or of individuals who were at an age when it would have been normal for them to have left the family. However, eye-witness testimony from slaves, such as Frederick Douglass, does not agree with this account. Frederick Douglass, who grew up as a slave in Maryland, reported the systematic separation of slave families. He also reports the widespread rape of slave women, in order to boost slave numbers. 
According to Genovese, slaves were fed, clothed, housed and provided medical care in the most minimal manner. It was common to pay small bonuses during the Christmas season, and some slave owners permitted their slaves to keep earnings and gambling profits. (One slave, Denmark Vesey, is known to have won a lottery and bought his freedom.) In many households, treatment of slaves varied with the slave's skin color. Darker-skinned slaves worked in the fields, while lighter-skinned house servants had comparatively better clothing, food and housing.
As in President Thomas Jefferson's household, the presence of lighter-skinned slaves as household servants was not merely an issue of skin color. Sometimes planters used mixed-race slaves as house servants or favored artisans because they were their children or other relatives. Several of Jefferson's household slaves were children of his father-in-law John Wayles and the enslaved woman Betty Hemings, who were brought to the marriage by Jefferson's wife. In turn the widower Jefferson had a long relationship with Betty and John Wayle's daughter Sally Hemings, a much younger enslaved woman who was mostly of white ancestry and half-sister to his late wife. The Hemings children grew up to be closely involved in Jefferson's household staff activities; one became his chef. Two sons trained as carpenters. Three of his four surviving mixed-race children with Sally Hemings passed into white society as adults.
Planters who had mixed-race children sometimes arranged for their education, even in schools in the North, or as apprentices in crafts. Others settled property on them. Some freed the children and their mothers. While fewer than in the Upper South, free blacks in the Deep South were more often mixed-race children of planters and were sometimes the recipients of transfers of property and social capital. For instance, Wilberforce University, founded by Methodist and African Methodist Episcopal (AME) representatives in Ohio in 1856 for the education of African-American youth, was in its first years largely supported by wealthy southern planters who paid for the education of their mixed-race children. When the war broke out, the school lost most of its 200 students. The college closed for a couple of years before the AME Church bought it and began to operate it.
Fogel argues that the material conditions of the lives of slaves compared favorably with those of free industrial workers. They were not good by modern standards, but this fact emphasizes the hard lot of all workers, free or slave, during the first half of the 19th century. Over the course of his lifetime, the typical slave field hand received about 90% of the income he produced. In a survey, 58% of historians and 42% of economists disagreed with the proposition that the material condition of slaves compared favorably with those of free industrial workers.
Slaves were considered legal non-persons except if they committed crimes. An Alabama court asserted that slaves "are rational beings, they are capable of committing crimes; and in reference to acts which are crimes, are regarded as persons. Because they are slaves, they are incapable of performing civil acts, and, in reference to all such, they are things, not persons."
In 1811, Arthur William Hodge was the first slave owner executed for the murder of a slave in the British West Indies. However, he was not, as some have claimed, the first white person to have been lawfully executed for the killing of a slave. Records indicate at least two earlier incidents. On November 23, 1739, in Williamsburg, Virginia, two white men, Charles Quin and David White, were hanged for the murder of another white man's black slave; and on April 21, 1775, the Fredericksburg newspaper, the Virginia Gazette reported that a white man William Pitman had been hanged for the murder of his own black slave.
To help regulate the relationship between slave and owner, including legal support for keeping the slave as property, slave codes were established. While each state would have their own, most of the ideas were shared throughout the slave states. In the codes for the District of Columbia, a slave is defined as “a human being, who is by law deprived of his or her liberty for life, and is the property of another.” A paragraph from the Black Code of South Carolina, still valid in 1863, declared death as the penalty for him who dared " to aid any slave in running away or departing from his master's or employer's service." Codes from other states placed limits on relations allowed between black and white people. Louisiana's Code Noir did not allow interracial marriage, and if children were a result a fine of three hundred livres would have to be paid. This code also stated children of a slave "shall share the condition of their mother”  if the child’s parents had different masters they would stay with the mother, and if the father was free and the mother a slave the children would also be slaves.
While working on plantations and farms, women and men had equal labor-intensive work. However, much of the hard labor was taken care of by men or by women who were past the child-bearing stage. Some of the labor-intensive jobs given to women were: cooking for the owner's household as well as the slaves themselves, sewing, midwifery, pruning fields, and many other laborious occupations.In 1837, an Antislavery Convention of American Women met in New York City with both black and white women participating. Lucretia Mott and Elizabeth Cady Stanton had first met at the convention and realized the need for a separate women's rights movement. At the London gathering Stanton also met other women delegates such as Emily Winslow, Abby Southwick, Elizabeth Neal, Mary Grew, Abby Kimber, as well as many other women. However, during the Massachusetts Anti-slavery Society meetings, which Stanton and Winslow attended, the hosts refused to seat the women delegates. This resulted in a convention of their own to form a "society to advocate the rights of women". In 1848 at Seneca Falls, New York, Stanton and Winslow launched the women's rights movement, becoming one of the most diverse and social forces in American life.
Beginning in the 1750s, there was widespread sentiment during the American Revolution that slavery was a social evil (for the country as a whole and for the whites) and should eventually be abolished. All the Northern states passed emancipation acts between 1780 and 1804; most of these arranged for gradual emancipation and a special status for freedmen, so there were still a dozen "permanent apprentices" in New Jersey in 1860.
Throughout the first half of the 19th century, a movement to end slavery grew in strength throughout the United States. This struggle took place amid strong support for slavery among white Southerners, who profited greatly from the system of enslaved labor. These slave owners began to refer to slavery as the "peculiar institution" in a defensive attempt to differentiate it from other examples of forced labor.
After 1830, a religious movement led by William Lloyd Garrison declared slavery to be a personal sin and demanded the owners repent immediately and start the process of emancipation. The movement was highly controversial and was a factor in causing the American Civil War.
Very few abolitionists, such as John Brown, favored the use of armed force to foment uprisings among the slaves; others tried to use the legal system.
Influential leaders of the abolition movement (1810-60) included:
Slave uprisings that used armed force (1700 - 1859) include:
The economic value of plantation slavery was magnified in 1793 with the invention of the cotton gin by Eli Whitney, a device designed to separate cotton fibers from seedpods and the sometimes sticky seeds. The invention revolutionized the cotton industry by increasing fiftyfold the quantity of cotton that could be processed in a day. The result was the explosive growth of the cotton industry and greatly increased the demand for slave labor in the South. 
At the same time, the northern states banned slavery, though, as Alexis de Toqueville noted in Democracy in America (1835), the prohibition did not always mean that the slaves were freed. Toqueville noted that as Northern states provided for gradual emancipation, they generally outlawed the sale of slaves within the state. This meant that the only way to sell slaves before they were freed was to move them South. Toqueville does not document that such transfers actually occurred much.  In fact, the emancipation of slaves in the North led to the growth in the population of northern free blacks, from several hundreds in the 1770s to nearly 50,000 by 1810. 
Just as demand for slaves was increasing, the supply was restricted. The United States Constitution, adopted in 1787, prevented Congress from banning the importation of slaves until 1808. On January 1, 1808, Congress banned further imports. Any new slaves would have to be descendants of ones currently in the United States. However, the internal American slave trade and the involvement in the international slave trade or the outfitting of ships for that trade by U.S. citizens were not banned. Though there were certainly violations of this law, slavery in America became, more or less, self-sustaining.
During the War of 1812, British Royal Navy commanders of the blockading fleet, based at the Bermuda dockyard, were given instructions to encourage the defection of American slaves by offering freedom, as they did during the Revolutionary War. Thousands of black slaves went over to the Crown with their families, and were recruited into the (3rd Colonial Battalion) Royal Marines on occupied Tangier Island, in the Chesapeake. A further company of colonial marines was raised at the Bermuda dockyard, where many freed slaves, men women and children, had been given refuge and employment. It was kept as a defensive force in case of an attack.
These former slaves fought for Britain throughout the Atlantic campaign, including the attack on Washington D.C.and the Louisiana Campaign, and most were later re-enlisted into British West India regiments, or settled in Trinidad in August, 1816, where seven hundred of these ex-marines were granted land (they reportedly organised themselves in villages along the lines of military companies). Many other freed American slaves were recruited directly into existing West Indian regiments, or newly created British Army units. A few thousand freed slaves were later settled at Nova Scotia by the British.
Slaveholders primarily in the South suffered considerable loss of property as tens of thousands of slaves escaped to British lines or ships for freedom, despite the difficulties. The planters' complacency about slave "contentment" was shocked by seeing slaves would risk so much to be free. Afterward, when some freed slaves had been settled at Bermuda, slaveholders such as Major Pierce Butler of South Carolina tried to persuade them to return to the United States, to no avail.
With the movement in Virginia and the Carolinas away from tobacco cultivation and toward mixed agriculture, which was less labor intensive, planters in those states had excess slave labor. They hired out some slaves for occasional labor, but planters also began to sell enslaved African Americans to traders who took them to markets in the Deep South for their expanding plantations. The internal slave trade and forced migration of enslaved African Americans continued for another half-century. Tens of thousands of slaves were transported from the Upper South, including Kentucky and Tennessee which became slave-selling states in these decades, to the Deep South. Thousands of African American families were broken up in the sales, which first concentrated on male laborers. The scale of the internal slave trade contributed substantially to the wealth of the Deep South. In 1840, New Orleans - which had the largest slave market and important shipping - was the third largest city in the country and the wealthiest.
Because of the three-fifths compromise in the U.S. Constitution, slaveholders exerted their power through the Federal Government and passed Federal fugitive slave laws. Refugees from slavery fled the South across the Ohio River and other parts of the Mason-Dixon Line dividing North from South, to the North via the Underground Railroad. The physical presence of African Americans in Cincinnati, Oberlin, and other Northern towns agitated some white Northerners, though others helped hide former slaves from their former owners, and others helped them reach freedom in Canada. After 1854, Republicans fumed that the Slave Power, especially the pro-slavery Democratic Party, controlled two of the three branches of the Federal government.
Most Northeastern states became free states through local emancipation. The settlement of the Midwestern states after the Revolution led to their decisions in the 1820s not to allow slavery. A Northern block of free states united into one contiguous geographic area which shared an anti-slavery culture. The boundary was the Mason-Dixon Line (between slave-state Maryland and free-state Pennsylvania) and the Ohio River.
North and South grew further apart in 1845 when the Baptist Church and other denominations split into Northern and Southern organizations. The Southern Baptist Convention formed on the premise that the Bible sanctions slavery and that it was acceptable for Christians to own slaves. (In the 20th century, the Southern Baptist Convention renounced this interpretation.) Currently American Baptist numerical strength is greatest in the former slave-holding states. Northern Baptists opposed slavery. In 1844, the Home Mission Society declared that a person could not be a missionary and still keep slaves as property. The Methodist and Presbyterian churches likewise divided north and south. By the late 1850s only the Democratic Party was a national institution, although it split in the 1860 election.
In 1831, a bloody slave rebellion took place in Southampton County, Virginia. A slave named Nat Turner, who was able to read and write and had "visions", started what became known as Nat Turner's Rebellion or the Southampton Insurrection. With the goal of freeing himself and others, Turner and his followers killed approximately fifty men, women and children, but they were eventually subdued by the militia.
Nat Turner and his followers were hanged, and Turner's body was flayed. The militia also killed more than a hundred slaves who had not been involved in the rebellion. Across the South, harsh new laws were enacted in the aftermath of the 1831 Turner Rebellion to curtail the already limited rights of African Americans. Typical was the following Virginia law against educating slaves, free blacks and children of whites and blacks:
. . . [E]very assemblage of negroes for the purpose of instruction in reading or writing, or in the night time for any purpose, shall be an unlawful assembly. Any justice may issue his warrant to any office or other person, requiring him to enter any place where such assemblage may be, and seize any negro therein; and he, or any other justice, may order such negro to be punished with stripes.
If a white person assemble with negroes for the purpose of instructing them to read or write, or if he associate with them in an unlawful assembly, he shall be confined in jail not exceeding six months and fined not exceeding one hundred dollars; and any justice may require him to enter into a recognizance, with sufficient security, to appear before the circuit, county or corporation court, of the county or corporation where the offence was committed, at its next term, to answer therefor[''sic''], and in the mean time to keep the peace and be of good behaviour.
After the passage of the Kansas-Nebraska Act, 1854, the border wars broke out in Kansas Territory, where the question of whether it would be admitted to the Union as a slave or free state was left to the inhabitants. Abolitionist John Brown was active in the rebellion and killing in "Bleeding Kansas" as were many white Southerners. At the same time, fears that the Slave Power was seizing full control of the national government swept anti-slavery Republicans into office.
Dred Scott was a 46 or 47-year old slave who sued for his freedom after the death of his owner on the grounds that he had lived in a territory where slavery was forbidden (the northern part of the Louisiana Purchase, from which slavery was excluded under the terms of the Missouri Compromise). Scott filed suit for freedom in 1846 and went through two state trials, the first denying and the second granting freedom. Eleven years later the Supreme Court denied Scott his freedom in a sweeping decision that set the United States on course for Civil War. The court ruled that Dred Scott was not a citizen who had a right to sue in the Federal courts, and that Congress had no constitutional power to pass the Missouri Compromise.
The 1857 Dred Scott decision, decided 7-2, held that a slave did not become free when taken into a free state; Congress could not bar slavery from a territory; and blacks could not be citizens. Furthermore, a state could not bar slaveowners from bringing slaves into that state. This decision, seen as unjust by many Republicans including Abraham Lincoln, was also seen as proof that the Slave Power had seized control of the Supreme Court. The decision, written by Chief Justice Roger B. Taney, barred slaves and their descendants from citizenship. The decision enraged abolitionists and encouraged slave owners, helping to push the country towards civil war.
The divisions became fully exposed with the 1860 presidential election. The electorate split four ways. The Southern Democrats endorsed slavery, while the Republicans denounced it. The Northern Democrats said democracy required the people to decide on slavery locally. The Constitutional Union Party said the survival of the Union was at stake and everything else should be compromised.
Lincoln, the Republican, won with a plurality of popular votes and a majority of electoral votes. Lincoln, however, did not appear on the ballots of ten southern states: thus his election necessarily split the nation along sectional lines. Many slave owners in the South feared that the real intent of the Republicans was the abolition of slavery in states where it already existed, and that the sudden emancipation of four million slaves would be problematic for the slave owners and for the economy that drew its greatest profits from the labor of people who were not paid.
They also argued that banning slavery in new states would upset what they saw as a delicate balance of free states and slave states. They feared that ending this balance could lead to the domination of the industrial North with its preference for high tariffs on imported goods. The combination of these factors led the South to secede from the Union, and thus began the American Civil War. Northern leaders had viewed the slavery interests as a threat politically, and with secession, they viewed the prospect of a new southern nation, the Confederate States of America, with control over the Mississippi River and the West, as politically and militarily unacceptable.
The consequent American Civil War, beginning in 1861, led to the end of chattel slavery in America. Not long after the war broke out, through a legal maneuver credited to Union General Benjamin F. Butler, a lawyer by profession, slaves who came into Union "possession" were considered "contraband of war". General Butler ruled that they were not subject to return to Confederate owners as they had been before the war. Soon word spread, and many slaves sought refuge in Union territory, desiring to be declared "contraband." Many of the "contrabands" joined the Union Army as workers or troops, forming entire regiments of the U.S. Colored Troops. Others went to refugee camps such as the Grand Contraband Camp near Fort Monroe or fled to northern cities. General Butler's interpretation was reinforced when Congress passed the Confiscation Act of 1861, which declared that any property used by the Confederate military, including slaves, could be confiscated by Union forces.
Lincoln's Emancipation Proclamation of January 1, 1863 was a powerful move that promised freedom for slaves in the Confederacy as soon as the Union armies reached them, and authorized the enlistment of African Americans in the Union Army. The Emancipation Proclamation did not free slaves in the Union-allied slave-holding states that bordered the Confederacy. Since the Confederate States did not recognize the authority of President Lincoln, and the proclamation did not apply in the border states, at first the proclamation freed only slaves who had escaped behind Union lines. Still, the proclamation made the abolition of slavery an official war goal that was implemented as the Union took territory from the Confederacy. According to the Census of 1860, this policy would free nearly four million slaves, or over 12% of the total population of the United States.
The Arizona Organic Act abolished slavery on February 24, 1863 in the newly formed Arizona Territory. Tennessee and all of the border states (except Kentucky) abolished slavery by early 1865. Thousands of slaves were freed by the operation of the Emancipation Proclamation as Union armies marched across the South. Emancipation as a reality came to the remaining southern slaves after the surrender of all Confederate troops in spring 1865.
At the beginning of the war, some Union commanders thought they were supposed to return escaped slaves to their masters. By 1862, when it became clear that this would be a long war, the question of what to do about slavery became more general. The Southern economy and military effort depended on slave labor. It began to seem unreasonable to protect slavery while blockading Southern commerce and destroying Southern production. As one Congressman put it, the slaves "…cannot be neutral. As laborers, if not as soldiers, they will be allies of the rebels, or of the Union." The same Congressman—and his fellow Radical Republicans—put pressure on Lincoln to rapidly emancipate the slaves, whereas moderate Republicans came to accept gradual, compensated emancipation and colonization. Copperheads, the border states and War Democrats opposed emancipation, although the border states and War Democrats eventually accepted it as part of total war needed to save the Union.
In 1861, Lincoln expressed the fear that premature attempts at emancipation would mean the loss of the border states. He believed that "to lose Kentucky is nearly the same as to lose the whole game." At first, Lincoln reversed attempts at emancipation by Secretary of War Simon Cameron and Generals John C. Fremont (in Missouri) and David Hunter (in South Carolina, Georgia and Florida) in order to keep the loyalty of the border states and the War Democrats.
Lincoln mentioned his Emancipation Proclamation to members of his cabinet on July 21, 1862. Secretary of State William H. Seward told Lincoln to wait for a victory before issuing the proclamation, as to do otherwise would seem like "our last shriek on the retreat". In September 1862 the Battle of Antietam provided this opportunity, and the subsequent War Governors' Conference added support for the proclamation. Lincoln had already published a letter encouraging the border states especially to accept emancipation as necessary to save the Union. Lincoln later said that slavery was "somehow the cause of the war". Lincoln issued his preliminary Emancipation Proclamation on September 22, 1862, and said that a final proclamation would be issued if his gradual plan based on compensated emancipation and voluntary colonization was rejected. Only the District of Columbia accepted Lincoln's gradual plan, and Lincoln issued his final Emancipation Proclamation on January 1, 1863. In his letter to Hodges, Lincoln explained his belief that "If slavery is not wrong, nothing is wrong … And yet I have never understood that the Presidency conferred upon me an unrestricted right to act officially upon this judgment and feeling ... I claim not to have controlled events, but confess plainly that events have controlled me."
Since the Emancipation Proclamation was based on the President's war powers, it only included territory held by Confederates at the time. However, the Proclamation became a symbol of the Union's growing commitment to add emancipation to the Union's definition of liberty. Lincoln also played a leading role in getting Congress to vote for the Thirteenth Amendment, which made emancipation universal and permanent.
Enslaved African Americans did not wait for Lincoln's action before escaping and seeking freedom behind Union lines. From early years of the war, hundreds of thousands of African Americans escaped to Union lines, especially in Union-controlled areas like Norfolk and the Hampton Roads region in 1862 Virginia, Tennessee from 1862 on, the line of Sherman's march, etc. So many African Americans fled to Union lines that commanders created camps and schools for them, where both adults and children learned to read and write. The American Missionary Association entered the war effort by sending teachers south to such contraband camps, for instance, establishing schools in Norfolk and on nearby plantations. In addition, nearly 200,000 African-American men served with distinction as soldiers and sailors with Union troops. Most of those were escaped slaves. Confederates enslaved captured black Union soldiers, and black soldiers especially were shot when trying to surrender at the Fort Pillow Massacre. This led to a breakdown of the prisoner exchange program, and the growth of prison camps such as Andersonville prison in Georgia, where almost 13,000 Union prisoners of war died of disease and starvation.
In spite of the South's shortage of manpower, until 1865, most Southern leaders opposed arming slaves as soldiers. However,a few Confederates discussed arming slaves since the early stages of the war, and some free blacks had even offered to fight for the South. In 1862 Georgian Congressman Warren Akin supported the enrolling of slaves with the promise of emancipation, as did the Alabama legislature. Support for doing so also grew in other Southern states. A few all black Confederate militia units, most notably the 1st Louisiana Native Guard, were formed in Louisiana at the start of the war, but were disbanded in 1862. In early March, 1865, Virginia endorsed a bill to enlist black soldiers, and on March 13 the Confederate Congress did the same.
There still were over 250,000 slaves in Texas. Word did not reach Texas about the collapse of the Confederacy until June 19, 1865. African Americans and others celebrate that day as Juneteenth, the day of freedom, in Texas, Oklahoma and some other states. It commemorates the date when the news finally reached slaves at Galveston, Texas.
Legally, the last 40,000 or so slaves were freed in Kentucky by the final ratification of the Thirteenth Amendment to the Constitution in December 1865. Slaves still held in New Jersey, Delaware, West Virginia, Maryland, Missouri and Washington, D.C. also became legally free on this date.
During Reconstruction, it was a serious question whether slavery had been permanently abolished or whether some form of semi-slavery would appear after the Union armies left. A large civil rights movement arose to to bring full civil rights and equality under the law to all Americans.
An 1867 federal law prohibited a descendant form of slavery known as sharecropping or debt bondage, which still existed in the New Mexico Territory as a legacy of Spanish imperial rule. Between 1903 and 1944, the Supreme Court ruled on several cases involving debt bondage of black Americans, declaring these arrangements unconstitutional. In actual practice, however, sharecropping arrangements often resulted in peonage for both black and white farmers in the South.
The anti-literacy laws after 1832 contributed greatly to the problem of widespread illiteracy facing the freedmen and other African Americans after Emancipation and the Civil War 35 years later. The problem of illiteracy and need for education was seen as one of the greatest challenges confronting these people as they sought to join the free enterprise system and support themselves during Reconstruction and thereafter.
Consequently, many black and white religious organizations, former Union Army officers and soldiers, and wealthy philanthropists were inspired to create and fund educational efforts specifically for the betterment of African Americans in the South. Blacks started their own schools even before the end of the war. Northerners helped create numerous normal schools, such as those that became Hampton University and Tuskegee University, to generate teachers. Blacks held teaching as a high calling, with education the first priority for children and adults. Many of the most talented went into the field. Some of the schools took years to reach a high standard, but they managed to get thousands of teachers started. As W.E.B. Du Bois noted, the black colleges were not perfect, but "in a single generation they put thirty thousand black teachers in the South" and "wiped out the illiteracy of the majority of black people in the land."
Northern philanthropists continued to support black education in the 20th century, even as tensions rose within the black community, exemplified by Dr. Booker T. Washington and Dr. W.E.B. Du Bois, as to the proper emphasis between industrial and classical academic education at the college level. Collaborating with Dr. Booker T. Washington in the early decades of the 20th century, philanthropist Julius Rosenwald provided matching funds for community efforts to build rural schools for black children. He insisted on white and black cooperation in the effort, wanting to ensure that white-controlled school boards made a commitment to maintain the schools. By the 1930s local parents had helped raise funds (sometimes donating labor and land) to create over 5,000 rural schools in the South. Other philanthropists such as Henry H. Rogers and Andrew Carnegie, each of whom had arisen from modest roots to become wealthy, used matching fund grants to stimulate local development of libraries and schools.
On February 24, 2007, the Virginia General Assembly passed House Joint Resolution Number 728 acknowledging "with profound regret the involuntary servitude of Africans and the exploitation of Native Americans, and call for reconciliation among all Virginians." With the passing of this resolution, Virginia became the first state to acknowledge through the state's governing body their state's negative involvement in slavery. The passing of this resolution came on the heels of the 400th anniversary celebration of the city of Jamestown, Virginia, which was one of the first slave ports of the American colonies.
In the 19th century, proponents of slavery often defended the institution as a "necessary evil". It was feared that emancipation would have more harmful social and economic consequences than the continuation of slavery. In 1820, Thomas Jefferson wrote in a letter that with slavery:
Robert E. Lee wrote in 1856:
However, as the abolition agitation increased and the planting system expanded, apologies for slavery became more faint in the South. Then apologies were superseded by claims that slavery was a beneficial scheme of labor control. John C. Calhoun, in a famous speech in the Senate in 1837, declared that slavery was "instead of an evil, a good—a positive good." Calhoun supported his view with the following reasoning: in every civilized society one portion of the community must live on the labor of another; learning, science, and the arts are built upon leisure; the African slave, kindly treated by his master and mistress and looked after in his old age, is better off than the free laborers of Europe; and under the slave system conflicts between capital and labor are avoided. The advantages of slavery in this respect, he concluded, "will become more and more manifest, if left undisturbed by interference from without, as the country advances in wealth and numbers."
Others who also moved from the idea of necessary evil to positive good are James Henry Hammond and George Fitzhugh. Hammond, like Calhoun, believed slavery was needed to build the rest of society. In a speech to the Senate on March 4, 1858, Hammond developed his Mudsill Theory defending his view on slavery stating, “Such a class you must have, or you would not have that other class which leads progress, civilization, and refinement. It constitutes the very mud-sill of society and of political government; and you might as well attempt to build a house in the air, as to build either the one or the other, except on this mud-sill.” He argued that the hired laborers of the North are slaves too: “The difference… is, that our slaves are hired for life and well compensated; there is no starvation, no begging, no want of employment,” while those in the North had to search for employment. George Fitzhugh wrote that, “the Negro is but a grown up child, and must be governed as a child.” In "The Universal Law of Slavery" Fitzhugh argues that slavery provides everything necessary for life and that the slave is unable to survive in a free world because he is lazy, and cannot compete with the intelligent European white race.
During the 17th century, Indian slavery, the enslavement of Native Americans by European colonists, was common. Many of these Native slaves were exported to off-shore colonies, especially the "sugar islands" of the Caribbean. Historian Alan Gallay estimates that from 1670-1715, British slave traders sold between 24,000 and 51,000 Native Americans from what is now the southern part of the U.S.
Slavery of Native Americans was organized in colonial and Mexican California through Franciscan missions, theoretically entitled to ten years of Native labor, but in practice maintaining them in perpetual servitude, until their charge was revoked in the mid-1830s. Following the 1847–1848 invasion by U.S. troops, Native Californians were enslaved in the new state from statehood in 1850 to 1867. Slavery required the posting of a bond by the slave holder and enslavement occurred through raids and a four-month servitude imposed as a punishment for Indian "vagrancy".
The Haida and Tlingit Indians who lived along southeast Alaska's coast were traditionally known as fierce warriors and slave-traders, raiding as far as California. Slavery was hereditary after slaves were taken as prisoners of war. Among some Pacific Northwest tribes, about a quarter of the population were slaves.  Other slave-owning tribes of North America were, for example, Comanche of Texas, Creek of Georgia, the fishing societies, such as the Yurok, that lived along the coast from what is now Alaska to California, the Pawnee, and Klamath.
The nature of slavery in Cherokee society often mirrored that of white slave-owning society. The law barred intermarriage of Cherokees and blacks, whether slave or free. Cherokee who aided slaves were punished with one hundred lashes on the back. In Cherokee society, blacks were barred from holding office, bearing arms, and owning property, and they made it illegal to teach blacks to read and write. 
According to Robert Davis, between 1 million and 1.25 million Europeans were captured by Barbary pirates and sold as slaves in North Africa and Ottoman Empire between the 16th and 19th centuries.  Because of the large numbers of Britons captured by the Barbary States and in other venues, captivity was the other side of exploration and empire. Captivity narratives originated as a literary form in the 17th century. They were widely published and read, preceding those of colonists captured by American Indians in North America. Slave-taking persisted into the 19th century when Barbary pirates would capture ships and enslave the crew. Between 1609 and 1616, England alone had 466 merchant ships lost to Barbary pirates.
United States commercial ships were not immune from pirate attacks. In 1783, the United States made peace with, and gained recognition from, the British monarchy. In 1784 the first American ship was seized by pirates from Morocco. By late 1793, a dozen American ships had been captured, goods stripped and everyone enslaved. After some serious debate, the government created the United States Navy in March 1794. This new military presence helped to stiffen American resolve to resist the continuation of tribute payments, leading to the two Barbary Wars along the North African coast: the First Barbary War from 1801 to 1805 and the Second Barbary War in 1815. Payments in ransom and tribute to the Barbary states had amounted to 20% of United States government annual revenues in 1800. It was not until 1815 that naval victories ended tribute payments by the U.S. Some European nations continued annual payments until the 1830s.
Some slaveholders were black or had some black ancestry. In 1830 there were 3,775 such slaveholders in the South, with 80% of them located in Louisiana, South Carolina, Virginia, and Maryland. There were economic differences between free blacks of the Upper South and Deep South, with the latter fewer in number, but wealthier and typically of mixed race. Half of the black slaveholders lived in cities rather than the countryside, with most in New Orleans and Charleston. Especially New Orleans had a large, relatively wealthy free black population (gens de couleur) composed of people of mixed race, who had become a third class between whites and enslaved blacks under French and Spanish rule. Relatively few slaveholders were “substantial planters.” Of those who were, most were of mixed race, often endowed by white fathers with some property and social capital. Historians John Hope Franklin and Loren Schweninger wrote:
Historian Ira Berlin wrote:
Free blacks were perceived “as a continual symbolic threat to slaveholders, challenging the idea that ‘black’ and ‘slave’ were synonymous.” Free blacks were seen as potential allies of fugitive slaves and “slaveholders bore witness to their fear and loathing of free blacks in no uncertain terms." For free blacks, who had only a precarious hold on freedom, “slave ownership was not simply an economic convenience but indispensable evidence of the free blacks” determination to break with their slave past and their silent acceptance – if not approval – of slavery.”
Historian James Oakes notes that, “The evidence is overwhelming that the vast majority of black slaveholders were free men who purchased members of their families or who acted out of benevolence.” After 1810 southern states made it increasingly difficult for any slaveholders to free slaves. Often the purchasers of family members were left with no choice but to maintain, on paper, the owner-slave relationship. In the 1850s “there were increasing efforts to restrict the right to hold bondsmen on the grounds that slaves should be kept ‘as far as possible under the control of white men only.”
In his 1985 statewide study of black slaveholders in South Carolina, Larry Koger challenged this benevolent view. He found that the majority of black slaveholders appeared to hold slaves as a commercial decision. For instance, he noted that in 1850 more than 80% of black slaveholders were of mixed race, but nearly 90% of their slaves were classified as black. He also noted the number of small artisans in Charleston who held slaves to help with their businesses.
Historian Peter Kolchin, writing in 1993, noted that until recently historians of slavery concentrated more on the behavior of slaveholders than on slaves. Part of this was related to the fact that most slaveholders were literate and able to leave behind a written record of their perspective. Most slaves were illiterate and unable to create a written record. There were differences among scholars as to whether slavery should be considered a benign or a “harshly exploitive” institution.
Kolchin described the state of historiography in the early twentieth century as follows:
Historians James Oliver Horton and Louise Horton described Phillips' mindset, methodology and influence:
The racist attitude concerning slaves carried over into the historiography of the Dunning School of reconstruction history, which dominated in the early 20th century. Writing in 2005, historian Eric Foner states:
Beginning in the 1930s and 1940s, historiography moved away from the “overt” racism of the Phillips era. However, historians still emphasized the slave as an object. Whereas Phillips presented the slave as the object of benign attention by the owners, historians such as Kenneth Stampp changed the emphasis to the mistreatment and abuse of the slave.
In the culmination of the slave as victim, Historian Stanley M. Elkins in his 1959 work “Slavery: A Problem in American Institutional and Intellectual Life” compared United States slavery to the brutality of the Nazi concentration camps. He stated the institution destroyed the will of the slave, creating an “emasculated, docile Sambo” who identified totally with the owner. Elkins' thesis immediately was challenged by historians. Gradually historians recognized that in addition to the effects of the owner-slave relationship, slaves did not live in a “totally closed environment but rather in one that permitted the emergence of enormous variety and allowed slaves to pursue important relationships with persons other than their master, including those to be found in their families, churches and communities.”
Robert W. Fogel and Stanley L. Engerman in the 1970s, through their work "Time on the Cross," presented the final attempt to salvage a version of the Sambo theory, picturing slaves as having internalized the Protestant work ethic of their owners. In portraying the more benign version of slavery, they also argue in their 1974 book that the material conditions under which the slaves lived and worked compared favorably to those of free workers in the agriculture and industry of the time.
In the 1970s and 1980s, historians made use of archaeological records, black folklore, and statistical data to describe a much more detailed and nuanced picture of slave life. Relying also on autobiographies of ex-slaves and former slave interviews conducted in the 1930s by the Federal Writers' Project, historians described slavery as the slaves experienced it. Far from slaves' being strictly victims or content, historians showed slaves as both resilient and autonomous in many of their activities. Despite the efforts at autonomy and their efforts to make a life within slavery, current historians recognize the precariousness of the slave's situation. Slave children quickly learned that they were subject to the direction of both their parents and their owners. They saw their parents disciplined just as they came to realize that they also could be physically or verbally abused by their owners. Historians writing during this era include John Blassingame (“Slave Community”), Eugene Genovese (“Roll, Jordon, Roll”), Leslie Howard Owens (“This Species of Property”), and Herbert Gutman (“The Black Family in Slavery and Freedom”).
Important work on slavery has continued; for instance, in 2003 Steven Hahn published the Pulitze Prize-winning account (A Nation under Our Feet: Black Political Struggles in the Rural South from Slavery to the Great Migration), which examined how slaves built community and political understanding even while enslaved, so they quickly began to form new associations and institutions when emancipated, including a black church separate from white control.
Although slave ownership by private individuals and businesses has been illegal in the United States since 1865, the Thirteenth Amendment to the United States Constitution specifically exempts the judiciary, permitting the enslavement of individuals "as a punishment for crime where of the party shall have been duly convicted".
The United States Department of Labor occasionally prosecutes cases against people for false imprisonment and involuntary servitude. These cases often involve illegal immigrants who are forced to work as slaves in factories to pay off a debt claimed by the people who transported them into the United States. Other cases have involved domestic workers.
The New York Times, ABC News, and The San Francisco Chronicle, among others, have reported on child and teenage sexual slavery in the United States. There are also reports on children working in organized criminal businesses and in legitimate businesses under both human and inhuman conditions.
In 2002, the U.S. Department of State repeated an earlier CIA estimate that each year, about 50,000 women and children are brought against their will to the United States for sexual exploitation. Former Secretary of State Colin Powell said that "Here and abroad, the victims of trafficking toil under inhuman conditions -- in brothels, sweatshops, fields and even in private homes."
Slave Narratives from the Federal Writers' Project, 1936-1938
Stanford researcher finds that slave trade artifacts were designed to convey messages of power, ownership, and even refinement.