The significant legislative act that abolished slavery in the United States was the 13th Amendment, passed in 1865. This amendment formally prohibited slavery and involuntary servitude, except as punishment for a crime. Ratified as a result of the Civil War and the broader abolitionist movement, it marked a transformative shift in American society. The 13th Amendment not only liberated millions of enslaved individuals but also laid the groundwork for subsequent civil rights advancements, including the 14th and 15th Amendments, which granted citizenship and voting rights to former slaves, fundamentally reshaping the nation's legal and moral landscape.