Which amendment abolished slavery in the United States?

The 13th Amendment is the correct answer as it explicitly abolished slavery throughout the United States. Ratified in 1865, this amendment marked a significant turning point in American history, effectively ending the legal practice of slavery and involuntary servitude except as punishment for a crime.

This constitutional change came in the aftermath of the Civil War, reflecting a crucial shift in national values towards freedom and human rights. The passage of the 13th Amendment was a monumental achievement for abolitionists and aligned with the broader movements for civil rights that would continue to evolve in the years to come.

In contrast, the 14th Amendment, ratified in 1868, primarily addressed citizenship rights and equal protection under the law. The 15th Amendment, ratified in 1870, focused on prohibiting the denial of the right to vote based on race, color, or previous condition of servitude. The 16th Amendment, ratified in 1913, dealt with the federal income tax and is unrelated to the issue of slavery. Thus, the significance and impact of the 13th Amendment in abolishing slavery is unparalleled among the choices presented.