Final answer:
The 13th Amendment to the US Constitution, ratified in 1865, abolished slavery and involuntary servitude, except as punishment for a convicted crime.
Step-by-step explanation:
The 13th Amendment of the US Constitution abolished slavery. This significant amendment was ratified at the end of the Civil War in December 1865, altering the legal framework of the United States by making slavery and involuntary servitude unconstitutional, except as a punishment for a crime where the individual has been duly convicted. The Thirteenth Amendment was a landmark in American legal history as it formally ended the institution of slavery that had existed in North America for 250 years.