On what date did the states ratify the Thirteenth Amendment to the U.S. Constitution?

The states ratified the Thirteenth Amendment to the U.S. Constitution on December 6, 1865.

The amendment abolished slavery and involuntary servitude in the United States, except as punishment for a crime after conviction. Congress passed it during the Civil War era, and the required three-fourths of the states approved it after the war’s end.

The House of Representatives passed the amendment on January 31, 1865. Georgia became the twenty-seventh state to ratify it on December 6, providing the required approval from 27 of the then 36 states.

Secretary of State William H. Seward proclaimed the amendment on December 18, 1865. That later proclamation date is why ratification and formal certification are sometimes mistakenly treated as the same event. The amendment was the first of the three Reconstruction Amendments.