Which U.S. constitutional amendment abolished slavery?

The Thirteenth Amendment abolished slavery in the United States, except as punishment for a crime after conviction.

Congress passed the amendment on January 31, 1865, and the required three-fourths of the states ratified it on December 6, 1865. Its first section states that slavery and involuntary servitude shall not exist within the United States or any place under its jurisdiction.

President Abraham Lincoln supported the amendment as the Civil War neared its end, and its ratification permanently changed the constitutional status of millions of enslaved people. The amendment gave Congress power to enforce its provisions through appropriate legislation.

The Fourteenth Amendment, ratified in 1868, addressed citizenship and equal protection. The Fifteenth Amendment, ratified in 1870, prohibited denying voting rights on racial grounds. Those amendments are related Reconstruction measures, but neither abolished slavery.