Slavery in the United States Slavery in the United States Slavery in the United States was the legal institution of human chattel enslavement, primarily of Africans and African Americans, that existed in the United States of America in the 18th and 19th centuries. Slavery had been practiced in British America from early colonial days, and was legal in all Thirteen Colonies at the time of the Declaration of Independence in 1776. It lasted in about half the states until 1865, when it was prohibited nationally by the Thirteenth Amendment. As an economic system, slavery was largely replaced by sharecropping. By the time of the American
United States Declaration of Independence against the colonies, "it is necessary that the exercise of every kind of authority under the said crown should be totally suppressed". Adams's preamble was meant to encourage the overthrow of the governments of Pennsylvania and Maryland, which were still under proprietary governance. Congress passed the preamble on May 15 after several days of debate, but four of the middle colonies voted against it, and the Maryland delegation walked out in protest. Adams regarded his May 15 preamble effectively as an American declaration of independence, although a formal declaration would still have to be made. On the same day that