James Armistead (later James Lafayette), an enslaved man, spies on British forces in Virginia for the marquis de Lafayette during the American Revolution.

Congress passed the first Fugitive Slave Act, making it a crime to harbor a person who escaped slavery or to interfere with his or her arrest.

The Missouri compromise is created stating that Missouri will be admitted as a Union state and that nothing above Missouri’s borders will be a slave state.

Enslaved Africans revolt on the Spanish slave ship Amistad near the coast of Cuba. The rebels are arrested in waters near New York. Former U.S. president John Quincy Adams successfully defends them before the Supreme Court.

Joseph Jenkins Roberts, the son of free Blacks in Virginia, is elected the first president of Liberia.

In an effort to maintain an even balance between free and slave states, the U.S. Congress passes a series of compromise measures. They include a new, stricter Fugitive Slave Act, which contributes to the spread of the abolitionist movement.

 In its Dred Scott decision, the U.S. Supreme Court legalizes slavery in all the territories. The decision increased tensions between the North and the South and pushed the country toward civil war.

After Abraham Lincoln wins the U.S. presidential election, South Carolina secedes from the Union in December. It was followed in January 1861 by Mississippi, Florida, Alabama, Georgia, and Louisiana, and in February by Texas. As battle lines are drawn, Virginia, North Carolina, Arkansas, and Tennessee also choose to secede.