In the United States, abolitionism, the movement that sought to end slavery in the country, was active from the colonial era until the American Civil War, the end of which brought about the abolition of American slavery, except as punishment for a crime, through the Thirteenth Amendment to the United States Constitution.

The legal institution of human chattel slavery, comprising the enslavement primarily of Africans and African Americans, was prevalent in the United States of America from its founding in 1776 until 1865, predominantly in the South. Slavery was established throughout European colonization in the Americas. From 1526, during the early colonial period, it was practiced in what became Britain's colonies, including the Thirteen Colonies that formed the United States. Under the law, an enslaved person was treated as property that could be bought, sold, or given away. Slavery lasted in about half of U.S. states until abolition in 1865, and issues concerning slavery seeped into every aspect of national politics, economics, and social custom. In the decades after the end of Reconstruction in 1877, many of slavery's economic and social functions were continued through segregation, sharecropping, and convict leasing.