Slavery began in the American colonies in the early 1500s as the Portuguese began bringing African slaves to the Americas. By 1700, slavery had grown significantly in the southern colonies, where the agricultural economy relied heavily on slave labor. To maintain control over the growing slave population, colonial governments passed slave codes that severely restricted slaves' rights and movement. Throughout this period, slaves resisted their condition through acts like slow work, escape attempts, and occasional rebellions like the large Stono Rebellion in South Carolina in 1739. By the end of the American Civil War in 1865, slavery was abolished across the United States.