The 13th Amendment to the U.S. Constitution declared that "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." Formally abolishing slavery in the United States, the 13th Amendment was passed by Congress on January 31, 1865, and ratified by the states on December 6, 1865.