Thirteenth Amendment to the United States Constitution

The Thirteenth Amendment (Amendment XIII) to the United States Constitution made slavery and involuntary servitude illegal, except as punishment for a crime. The amendment was passed by the Senate on April 8, 1864, by the House of Representatives on January 31, 1865, and ratified by the required 27 of the then 36 states on December 6, 1865, and proclaimed on December 18, 1865. It was the first of the three Reconstruction Amendments adopted following the American Civil War.

President Abraham Lincoln's Emancipation Proclamation, effective on January 1, 1863, declared that the enslaved in Confederate-controlled areas (and thus almost all slaves) were free. When they escaped to Union lines or federal forces (including now-former slaves) advanced south, emancipation occurred without any compensation to the former owners. Texas was the last Confederate slave state, where enforcement of the proclamation was declared on June 19, 1865. In the slave-owning areas controlled by Union forces on January 1, 1863, state action was used to abolish slavery. The exceptions were Kentucky and Delaware, where chattel slavery and indentured servitude were finally ended by the Thirteenth Amendment in December 1865.

In contrast to the other Reconstruction Amendments, the Thirteenth Amendment has rarely been cited in case law, but it has been used to strike down peonage and some race-based discrimination as "badges and incidents of slavery". The Thirteenth Amendment has also been invoked to empower Congress to make laws against modern forms of slavery, such as sex trafficking. It was the first amendment to directly govern private individuals instead of just the government.