1619
The first slaves to work on the North American mainland arrive at the Jamestown, Virginia, colony.

1688
The Quakers of Pennsylvania publish the first antislavery document in North America.

1776
Representatives of the British colonists adopt the Declaration of Independence, which grants "life, liberty, and hap-piness" as natural rights.

1787
By the Northwest Ordinance, written by Thomas Jefferson of Virginia, slavery is banned in new colonies acquired from Great Britain.

1788
The U.S. Constitution is ratified, allowing for slaveholding states to count slaves as three-fifths of a person when determining congressional representation.

1793
By the passage of the first Fugitive Slave Act, escaped slaves must be returned across state lines to their owners; Eli Whitney invents the cotton gin, an important factor in the growth of Southern cotton plantations dependent on slave labor.

1807
Following the U.S. Constitution, which decreed an end to the transatlantic slave trade after twenty years, Congress passes...