The Thirteenth Amendment to the United States Constitution abolished slavery and involuntary servitude, 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. It was the first of the three Reconstruction Amendments adopted following the American Civil War. The Thirteenth Amendment changed a portion of Article IV, Section 2 of the Constitution.