Slavery was legal in what became the United States for roughly 246 years, measured from the arrival of enslaved Africans at Jamestown, Virginia, in August 1619 to the ratification of the Thirteenth Amendment on December 6, 1865. Over that span it grew from an informal colonial practice into an institution written into the Constitution and enforced by federal marshals. Ending it took a civil war and an amendment to the nation’s highest law.
Why the Count Starts in 1619
The conventional starting date is August 1619, when roughly twenty captured Africans arrived at Jamestown aboard a privateer and were traded for provisions. That was not the first instance of slavery on the continent. Spanish colonizers brought enslaved Africans to what is now South Carolina as early as 1526, and enslaved people were present at the founding of St. Augustine, Florida, in 1565.1Library of Congress. Beyond 1619: Slavery and the Cultures of America The 246-year figure uses 1619 because that is when slavery took root in the English colonies whose legal traditions carried forward into the United States.
When Slavery Became Explicitly Legal
For the first few decades after 1619, the legal line between enslaved people and indentured servants was blurry. That changed in 1641, when the Massachusetts Body of Liberties became the first colonial document to give slavery an explicit legal footing. Liberty 91 stated that there would be no “bond slaverie” in the colony unless the people in question were “lawfull Captives taken in just warres” or strangers who sold themselves voluntarily.2Online Library of Liberty. 1641 Massachusetts Body of Liberties The language sounds restrictive, but it opened the door to permanent, legally sanctioned bondage in English North America.
Virginia pushed the door the rest of the way. In 1662, the colony passed a law declaring that a child’s free or enslaved status would follow the condition of the mother, not the father. This reversed English common law, which traced status through the father, and it created a self-perpetuating system: any child born to an enslaved woman was automatically enslaved regardless of paternity.3Encyclopedia Virginia. Negro Womens Children to Serve According to the Condition of the Mother (1662) Enslavers no longer needed to import people to grow their labor force. It grew itself.
By 1705, Virginia had consolidated its scattered laws into the Act Concerning Servants and Slaves. It declared that all non-Christian servants imported into the colony would “be accounted and be slaves” and could be bought and sold, barred enslaved people from owning property, and established racial criteria for perpetual servitude.4Encyclopedia Virginia. An Act Concerning Servants and Slaves Other colonies adopted similar codes. By the mid-1700s, slavery was a legal institution in every colony along the Atlantic coast.
How the Constitution Locked Slavery In
When the states drafted the Constitution in 1787, slavery was already the economic engine of the South. The document never uses the word “slave,” but three of its provisions were designed to protect the institution.
The Three-Fifths Clause in Article I, Section 2 directed that congressional representation would be calculated by “adding to the whole Number of free Persons… three fifths of all other Persons.”5Congress.gov. Constitution Annotated – Article 1 Section 2 Clause 3 Enslaved people could not vote, but their existence inflated the political power of the states that held them in the House and the Electoral College.
Article I, Section 9 barred Congress from prohibiting the “Migration or Importation” of enslaved people before 1808.6Congress.gov. Article 1 Section 9 Clause 1 Congress acted at the earliest possible moment, passing the Act Prohibiting Importation of Slaves in March 1807, effective January 1, 1808, with fines up to $10,000 and imprisonment for participants. Illegal smuggling continued for decades, but the legal transatlantic trade ended on that date. Slavery itself did not.
The Fugitive Slave Clause in Article IV, Section 2 reached into free states. It required that any person “held to Service or Labour in one State” who escaped into another “shall be delivered up on Claim of the Party to whom such Service or Labour may be due.”7Congress.gov. Fugitive Slave Clause Crossing into a free jurisdiction did not free an enslaved person, and the federal government was obligated to help return them. The Fugitive Slave Act of 1850 sharpened that obligation, imposing fines up to $1,000 and up to six months in prison on anyone who helped a person escape, with civil damages of $1,000 per person. The commissioners hearing these cases were paid $10 for ruling in favor of the person claiming ownership and $5 for ruling in favor of the accused.8Avalon Project. Fugitive Slave Act 1850
When Slavery Ended: Proclamation and Amendment
President Abraham Lincoln issued the Emancipation Proclamation on January 1, 1863, declaring that all enslaved people in states “in rebellion against the United States” were “henceforward shall be free.”9National Archives. Emancipation Proclamation (1863) Lincoln issued it under his authority as Commander-in-Chief, framing it as a military measure to weaken the Confederacy.
The Proclamation had sharp legal limits. It applied only to Confederate states and explicitly exempted Union-controlled areas, including specific parishes in Louisiana and counties in Virginia.10Avalon Project. Emancipation Proclamation The loyal border states of Delaware, Maryland, Kentucky, Missouri, and West Virginia were untouched, and hundreds of thousands of people in those states remained legally enslaved. Because the order was an executive war measure rather than a law or amendment, its permanence was uncertain. A negotiated peace or a future president could unwind it.
The permanent end came with the Thirteenth Amendment. The Senate passed it on April 8, 1864, by a vote of 38 to 6.11U.S. Senate. The Senate Passes the Thirteenth Amendment The House approved it on January 31, 1865, by 119 to 56.12National Archives. 13th Amendment to the U.S. Constitution: Abolition of Slavery Ratification by three-quarters of the states was completed on December 6, 1865. Section 1 reads: “Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction.”13Congress.gov. Thirteenth Amendment Every state and federal law permitting slavery was voided on that date. The Fugitive Slave Clause, the Three-Fifths Clause, and the legal architecture built over 246 years became dead letters.
Some states did not ratify voluntarily at the time. Kentucky’s legislature voted against the amendment on February 24, 1865, and did not formally ratify until 1976. Delaware rejected it in 1865 and did not officially ratify until 1901. The amendment took effect anyway once the required number of states approved it, binding even those that voted no.
The Exception That Outlived Abolition
The Thirteenth Amendment abolished slavery with one exception: “as a punishment for crime.” Within months of ratification, former Confederate states passed Black Codes that criminalized Black life in ways designed to recreate forced labor under a different name. Vagrancy laws made it a crime for a Black person to be unemployed and without a permanent residence, with those who could not pay the fine “bound out for a term of labour.” Apprentice laws authorized courts to hire out orphaned or dependent Black children to white employers, frequently their former enslavers.
These laws fed the convict leasing system, in which states leased incarcerated people to private companies for mining, railroad construction, and plantation work. The legal justification rested on the punishment clause. Republican sponsors of the amendment rejected the reading that the clause authorized anything resembling slavery, arguing it covered only genuine criminal punishment. Southern states adopted the broader reading, and federal authorities did not intervene after Reconstruction ended. The formal legal period of slavery lasted 246 years; the legal structures that grew from it lasted considerably longer.