The Thirteenth Amendment, ratified on December 6, 1865, ended slavery for every person still legally enslaved in the United States. In practical terms, it applied to the roughly four million people the 1860 Census had counted as enslaved, but the number it actually freed on the day of ratification was far smaller: most had already been freed during the Civil War through the Emancipation Proclamation, the advance of Union forces, and state-level abolition. The amendment’s direct legal effect fell on the people still held in bondage in Kentucky and Delaware, together with anyone in the former Confederacy whose freedom had not yet been enforced on the ground.
The Four Million Figure
The 1860 Census counted just under four million enslaved people in the United States, with totals in different tabulations ranging from about 3,950,000 to 3,954,000 across fifteen states and the District of Columbia.1Library of Congress. Mapping Slavery2National Center for Biotechnology Information. Enslaved Population in 1860 Census That was roughly one-eighth of the country’s population. About 3.5 million lived in the eleven Confederate states. The largest concentrations were in Virginia (about 491,000), Georgia (462,000), Mississippi (437,000), Alabama (435,000), and South Carolina (402,000).3University of Maryland. Population Statistics, 1860
Another 432,586 enslaved people lived in the four Union border states — Delaware, Kentucky, Maryland, and Missouri — and the District of Columbia. Kentucky alone accounted for more than 225,000 of those.3University of Maryland. Population Statistics, 1860
Four million is the number most often cited for the amendment’s reach because it represents the enslaved population that existed at the start of the war. It is not, however, the number of people still awaiting emancipation when the amendment was ratified.
Who Had Already Been Freed Before December 1865
By the time Georgia’s ratification vote pushed the Thirteenth Amendment over the three-fourths threshold, several waves of emancipation had already come and gone.
The Emancipation Proclamation and the Union Army
President Abraham Lincoln issued the Emancipation Proclamation on January 1, 1863, declaring that “all persons held as slaves” in states then in rebellion were free.4National Archives. The Emancipation Proclamation The order was a wartime measure with real gaps. It did not apply to the four loyal border states. It also expressly exempted Tennessee, thirteen Louisiana parishes including New Orleans, the forty-eight western Virginia counties that had become West Virginia, and several eastern Virginia counties around Norfolk. About 800,000 enslaved people fell into these exempted categories.5Prairie View A&M University. Juneteenth: The Emancipation Proclamation, Freedom Realized and Delayed
Where the Proclamation did apply, freedom depended on Union military control. Historian William C. Harris has estimated that by the war’s end, the Proclamation combined with the Army’s advance had freed more than one million enslaved people.6American Civil War Museum. Myths and Misunderstandings: The Emancipation Proclamation The pace was uneven. On June 19, 1865, more than two years after the Proclamation and more than two months after the Confederate surrender, Major General Gordon Granger arrived in Galveston and issued General Order No. 3, informing the more than 250,000 enslaved people in Texas that they were free.7Britannica. General Order No. 3 That date is now marked as Juneteenth.
State-Level Abolition
Several jurisdictions ended slavery on their own before the amendment was ratified:
- The District of Columbia freed 2,989 enslaved people under the DC Emancipation Act on April 16, 1862.8National Archives Foundation. The Emancipation Proclamation
- Maryland freed roughly 87,000 people through a new state constitution that took effect on November 1, 1864.9Equity in History. Juneteenth: When Were Maryland’s Slaves Freed
- Missouri abolished slavery on January 11, 1865, when a state constitutional convention passed an emancipation ordinance with only four dissenting votes.10Missouri Secretary of State. Missouri’s Abolition of Slavery
Who Was Still Enslaved When the Amendment Was Ratified
Two Union states never abolished slavery on their own. Kentucky held more than 225,000 enslaved people, and Delaware held nearly 1,800, right up to the moment the Thirteenth Amendment was ratified.9Equity in History. Juneteenth: When Were Maryland’s Slaves Freed For those people, the amendment was the instrument of freedom. Everyone else the amendment reached had either been covered by the Proclamation, freed by a state action, or had freedom confirmed on paper after the Army had already delivered it in fact.
So the honest answer to the counting question has two parts. The amendment made abolition permanent and universal for the roughly four million people counted as enslaved in 1860, closing the gap the Proclamation had left open. Its direct emancipatory effect on the day of ratification was concentrated on the more than 225,000 people still enslaved in Kentucky and the nearly 1,800 in Delaware — a figure sometimes rounded up when residual pockets in Confederate territory are included.
What the Amendment Did That the Proclamation Could Not
Lincoln and Republican leaders in Congress pushed for a constitutional amendment because the Emancipation Proclamation was a wartime executive order with no guarantee of surviving peace. A future president or Congress could revoke it, and courts might rule it invalid once hostilities ended.11U.S. Senate. Senate Passes the Thirteenth Amendment A constitutional amendment closed those doors.
The text is short. Section 1 provides: “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.” Section 2 gives Congress the power to enforce the amendment through legislation.12Congress.gov. 13th Amendment
Two features distinguish it from the Proclamation. First, it applied everywhere in the United States, including the border states and the exempted parts of the Confederacy. Second, unlike the Fourteenth Amendment, which reaches only state action, the Thirteenth reaches private conduct as well. The Supreme Court held in the 1883 Civil Rights Cases that the amendment is self-executing and that Congress may legislate against the “badges and incidents of slavery” even when those are imposed by private individuals.13Congress.gov. Thirteenth Amendment, Section 2
The Punishment Exception
One boundary is worth naming, because the amendment’s ban on slavery is not absolute on its face. The eleven words “except as a punishment for crime whereof the party shall have been duly convicted” carved out an exception that Southern legislatures exploited almost immediately, passing “Black Codes” that criminalized everyday conduct by Black people and then leasing convicts to private railroads, mines, plantations, and manufacturers.14Equal Justice Initiative. History of Racial Injustice: Convict Leasing15Library of Congress. Convict Leasing System Convict leasing persisted into the twentieth century. The exception is still in the constitutional text today, though seven states — Colorado, Nebraska, Utah, Alabama, Oregon, Tennessee, and Vermont — have removed equivalent language from their own state constitutions between 2018 and 2022.16NAACP Legal Defense Fund. 13th Amendment: From Emancipation to Mass Incarceration
The counting answer, in one line: the Thirteenth Amendment abolished slavery for the roughly four million people the 1860 Census had recorded as enslaved, but by December 6, 1865, most of them had already been freed by other means, and the amendment’s day-of-ratification effect fell most directly on the more than 225,000 people still enslaved in Kentucky and the nearly 1,800 in Delaware.