U.S. Slavery: Timeline, Figures & Abolition (2023)

When Did Slavery Start in America?

In the 17th and 18th centuries, enslaved Africans worked mainly on the tobacco, rice and indigo plantations of the southern coast, from the Chesapeake Bay colonies of Maryland and Virginia south to Georgia.

After the American Revolution, many colonists—particularly in the North, where slavery was relatively unimportant to the agricultural economy—began to link the oppression of enslaved Africans to their own oppression by the British, and to call for slavery’s abolition.

But after the Revolutionary War, the new U.S. Constitution tacitly acknowledged the institution of slavery, when it valued each enslaved individual as three-fifths of a person for the purposes of taxation and representation in Congress. The Constitution's drafters also guaranteed the right to repossess any “person held to service or labor” (an obvious euphemism for slavery).

Throughout the 17th and 18th centuries, people were kidnapped from the continent of Africa, forced into slavery in the American colonies and exploited to work in the production of crops such as tobacco and cotton.

By the mid-19th century, America’s westward expansion and the abolition movement provoked a great debate over slavery that would tear the nation apart in the bloody Civil War. Though the Union victory freed the nation’s four million enslaved people, the legacy of slavery continued to influence American history, from the Reconstruction to the civil rights movement that emerged a century after emancipation and beyond.

Cotton Gin

In the late 18th century, with the land used to grow tobacco nearly exhausted, the South faced an economic crisis, and the continued growth of slavery in America seemed in doubt.

Around the same time, the mechanization of the textile industry in England led to a huge demand for American cotton, a southern crop whose production was limited by the difficulty of removing the seeds from raw cotton fibers by hand.

But in 1793, a young Yankee schoolteacher named Eli Whitney invented the cotton gin, a simple mechanized device that efficiently removed the seeds. His device was widely copied, and within a few years, the South transitioned from the large-scale production of tobacco to that of cotton, a switch that reinforced the region’s dependence on enslaved labor.

Slavery itself was never widespread in the North, though many of the region’s businessmen grew rich on the slave trade and investments in southern plantations. Between 1774 and 1804, most of the northern states abolished slavery or started the process to abolish slavery, but the institution of slavery remained vital to the South.

Though the U.S. Congress outlawed the African slave trade in 1808, the domestic trade flourished, and the enslaved population in the United States nearly tripled over the next 50 years. By 1860 it had reached nearly 4 million, with more than half living in the cotton-producing states of the South.

Living Conditions of Enslaved People

Enslaved people in the antebellum South constituted about one-third of the southern population. Most lived on large plantations or small farms; many masters owned fewer than 50 enslaved people.

Landowners sought to make their enslaved completely dependent on them through a system of restrictive codes. They were usually prohibited from learning to read and write, and their behavior and movement were restricted.

Many masters raped enslaved women, and rewarded obedient behavior with favors, while rebellious enslaved people were brutally punished. A strict hierarchy among the enslaved (from privileged house workers and skilled artisans down to lowly field hands) helped keep them divided and less likely to organize against their masters.

Marriages between enslaved men and women had no legal basis, but many did marry and raise large families. Most owners of enslaved workers encouraged this practice, but nonetheless did not usually hesitate to divide families by sale or removal.

Slave Rebellions

Rebellionsamong enslaved people did occur—notably, ones led by Gabriel Prosser in Richmond in 1800 and by Denmark Vesey in Charleston in 1822—but few were successful.

The revolt that most terrified enslavers was that led by Nat Turner in Southampton County, Virginia, in August 1831. Turner’s group, which eventually numbered around 75 Black men, murdered some 55 white people in two days before armed resistance from local white people and the arrival of state militia forces overwhelmed them.

Supporters of slavery pointed to Turner’s rebellion as evidence that Black people were inherently inferior barbarians requiring an institution such as slavery to discipline them. And fears of similar insurrections led many southern states to further strengthen their slave codes in order to limit the education, movement and assembly of enslaved people.

Abolitionist Movement

In the North, the increased repression of southern Black people only fanned the flames of the growing abolitionist movement.

From the 1830s to the 1860s, the movement to abolish slavery in America gained strength, led by free Black peoplesuch as Frederick Douglass and white supporters such as William Lloyd Garrison, founder of the radical newspaper The Liberator, and Harriet Beecher Stowe, who published the bestselling antislavery novel Uncle Tom’s Cabin.

While many abolitionists based their activism on the belief that slaveholding was a sin, others were more inclined to the non-religious “free-labor” argument, which held that slaveholding was regressive, inefficient and made little economic sense.

Free Black people and other antislavery northerners had begun helping enslaved people escape from southern plantations to the North via a loose network of safe houses as early as the 1780s. This practice, known as the Underground Railroad, gained real momentum in the 1830s.

Conductors like Harriet Tubman guided escapees on their journey North, and “stationmasters” included such prominent figures as Frederick Douglass, Secretary of State William H. Seward and Pennsylvania congressman Thaddeus Stevens. Although estimates vary widely, it may have helped anywhere from 40,000 to 100,000 enslaved people reach freedom.

The success of the Underground Railroad helped spread abolitionist feelings in the North. It also undoubtedly increased sectional tensions, convincing pro-slavery southerners of their northern countrymen’s determination to defeat the institution that sustained them.

Missouri Compromise

America’s explosive growth—and its expansion westward in the first half of the 19th century—would provide a larger stage for the growing conflict over slavery in America and its future limitation or expansion.

In 1820, a bitter debate over the federal government’s right to restrict slavery over Missouri’s application for statehood ended in a compromise: Missouri was admitted to the Union as a slave state, Maine as a free state and all western territories north of Missouri’s southern border were to be free soil.

Although the Missouri Compromise was designed to maintain an even balance between slave and free states, it was only temporarily able to help quell the forces of sectionalism.

Kansas-Nebraska Act

In 1850, another tenuous compromise was negotiated to resolve the question of slavery in territories won during the Mexican-American War.

Four years later, however, the Kansas-Nebraska Act opened all new territories to slavery by asserting the rule of popular sovereignty over congressional edict, leading pro- and anti-slavery forces to battle it out—with considerable bloodshed—in the new state of Kansas.

Outrage in the North over the Kansas-Nebraska Act spelled the downfall of the old Whig Party and the birth of a new, all-northern Republican Party. In 1857, the Dred Scott decision by the Supreme Court (involving an enslaved man who sued for his freedom on the grounds that his master had taken him into free territory) effectively repealed the Missouri Compromise by ruling that all territories were open to slavery.

John Brown’s Raid on Harper’s Ferry

In 1859, two years after the Dred Scott decision, an event occurred that would ignite passions nationwide over the issue of slavery.

John Brown’s raid on Harper’s Ferry, Virginia—in which the abolitionist and 22 men, including five Black men and three of Brown’s sons raided and occupied a federal arsenal—resulted in the deaths of 10 people and Brown’s hanging.

The insurrection exposed the growing national rift over slavery: Brown was hailed as a martyred hero by northern abolitionists but was vilified as a mass murderer in the South.

Civil War

The South would reach the breaking point the following year, when Republican candidate Abraham Lincoln was elected as president. Within three months, seven southern states had seceded to form the Confederate States of America; four more would follow after the Civil War began.

Though Lincoln’s anti-slavery views were well established, the central Union war aim at first was not to abolish slavery, but to preserve the United States as a nation.

Abolition became a goal only later, due to military necessity, growing anti-slavery sentiment in the North and the self-emancipation of many people who fled enslavement as Union troops swept through the South.

When Did Slavery End?

On September 22, 1862, Lincoln issued a preliminary emancipation proclamation, and on January 1, 1863, he made it official that “slaves within any State, or designated part of a State…in rebellion,…shall be then, thenceforward, and forever free.”

By freeing some 3 million enslaved people in the rebel states, the Emancipation Proclamation deprived the Confederacy of the bulk of its labor forces and put international public opinion strongly on the Union side.

Though the Emancipation Proclamation didn’t officially end all slavery in America—that would happen with the passage of the 13th Amendment after the Civil War’s end in 1865—some 186,000 Black soldiers would join the Union Army, and about 38,000 lost their lives.

The Legacy of Slavery

The 13th Amendment, adopted on December 18, 1865, officially abolished slavery, but freed Black peoples’ status in the post-war South remained precarious, and significant challenges awaited during the Reconstruction period.

Previously enslaved men and women received the rights of citizenship and the “equal protection” of the Constitution in the 14th Amendment and the right to vote in the 15th Amendment, but these provisions of the Constitution were often ignored or violated, and it was difficult for Black citizens to gain a foothold in the post-war economy thanks to restrictive Black codes and regressive contractual arrangements such as sharecropping.

Despite seeing an unprecedented degree of Black participation in American political life, Reconstruction was ultimately frustrating for African Americans, and the rebirth of white supremacy—including the rise of racist organizations such as the Ku Klux Klan (KKK)—had triumphed in the South by 1877.

Almost a century later, resistance to the lingering racism and discrimination in America that began during the slavery era led to the civil rights movement of the 1960s, which achieved the greatest political and social gains for Black Americans since Reconstruction.