Which amendment abolished slavery in the United States?

The Thirteenth Amendment abolished slavery in the United States. Ratified in December 1865, this amendment states that neither slavery nor involuntary servitude shall exist within the United States, except as punishment for a crime. Its adoption marked a significant turning point in American history, as it legally ended the institution of slavery, which had been a source of immense human rights violations and social conflict.

The other amendments do not address the issue of slavery. The Fifteenth Amendment, for example, focuses on the right to vote, prohibiting the federal and state governments from denying a citizen the right to vote based on "race, color, or previous condition of servitude." The Twentieth Amendment deals with the terms of office for the president and members of Congress, and the Seventeenth Amendment outlines the direct election of U.S. Senators. Therefore, the Thirteenth Amendment is the correct answer as it specifically and directly abolished slavery.