What is the purpose of the 13th amendment?

Passed by Congress on January 31, 1865, and ratified on December 6, 1865, the 13th amendment abolished slavery in the United States and provides 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

The Thirteenth Amendment to the United States Constitution abolished slavery and involuntary servitude, except as punishment for a crime.