The U.S. Congress passes an act to "prohibit the importation of slaves into any port or place within the jurisdiction of the United States...from any foreign kingdom, place, or country."
The first shipload of African captives to North America arrived at Jamestown, Virginia, in August 1619, but for most of the 17th century, European indentured servants were far more numerous in the North American British colonies than were African slaves. However, after 1680, the flow of indentured servants sharply declined, leading to an explosion in the African slave trade. By the middle of the 18th century, slavery could be found in all 13 colonies and was at the core of the Southern colonies' agricultural economy. By the time of the American Revolution, the English importers alone had brought some three million captive Africans to the Americas.
After the war, as slave labor was not a crucial element of the Northern economy, most Northern states passed legislation to abolish slavery. However, in the South, the invention of the cotton gin in 1793 made cotton a major industry and sharply increased the need for slave labor. Tension arose between the North and the South as the slave or free status of new states was debated. In January 1807, with a self-sustaining population of over four million slaves in the South, some Southern congressmen joined with the North in voting to abolish the African slave trade, an act that became effective January 1, 1808. The widespread trade of slaves within the South was not prohibited, however, and children of slaves automatically became slave themselves, thus ensuring a self-sustaining slave population in the South.
Great Britain also banned the African slave trade in 1807, but the trade of African slaves to Brazil and Cuba continued until the 1860s. By 1865, some 12 million Africans had been shipped across the Atlantic Ocean to the Americas, and more than one million of these individuals had died from mistreatment during the voyage. In addition, an unknown number of Africans died in slave wars and forced marches directly resulting from the Western Hemisphere's demand for African slaves.