Which amendment abolished slavery in the United States?

The 13th Amendment to the United States Constitution is the pivotal legislative act that abolished slavery. Ratified on December 6, 1865, this amendment marked a significant turning point in American history by formally outlawing the practice of slavery and involuntary servitude, except as punishment for a crime. This amendment was a direct consequence of the Civil War and was a fundamental step towards civil rights and equality, reflecting the country's commitment to ending the institution that had perpetuated deep social and racial injustices.

In contrast, the other amendments mentioned serve different purposes: the 15th Amendment addresses voting rights by prohibiting the federal and state governments from denying a citizen the right to vote based on "race, color, or previous condition of servitude." The 14th Amendment deals with citizenship rights and equal protection under the law, while the 12th Amendment modifies the procedure for electing the President and Vice President. These distinctions underscore the unique and critical role of the 13th Amendment in shaping the legal landscape of freedom and human rights in the United States.