American Civil War

According to Confederate leaders, the defense of slavery was the primary reason for secession.

The trans-Atlantic slave trade brought over 10 million enslaved people to the Americas.

View animated battle maps from every major skirmish of the American Civil War.

US westward expansion—and the status of slavery in the new territories—was a major cause of the American Civil War

The addition of new western lands forced the nation to confront whether slavery would spread beyond the South. Each debate over the admission of a new state sharpened the divide between free and slaveholding regions.

Abraham Lincoln's victory in 1860 sparked Southern secession—even before his inauguration

Abraham Lincoln's election on an antislavery expansion platform convinced many Southerners that their way of life was under threat. Within three months, seven states seceded from the Union—forming the Confederacy—before Lincoln took office in March 1861.

Abraham Lincoln received only 40% of the popular vote in the 1860 election

Lincoln's 1860 victory came entirely from Northern and Western states, as his name was excluded from most Southern ballots. The outcome highlighted the deep divisions and regional polarization in the country.

Abraham Lincoln's election in 1860 triggered a cascade of Southern secessions and the formation of the Confederacy, culminating in the Confederate attack on Fort Sumter in Charleston, SC.

11 states formed the Confederacy, with 2 others claiming allegiance

Between December 1860 and June 1861, 11 Southern states officially seceded to form the Confederacy. Pro-Confederate factions in Missouri and Kentucky also declared secession, but both states remained largely under Union control throughout the war.

Lincoln's Gettysburg Address became one of the most famous speeches in American history

Delivered by Lincoln on Nov. 19, 1863, at the dedication of a national cemetery, the 272-word Gettysburg Address reframed the war as a struggle for equality. The speech would be cited as a moral touchstone for later movements such as women's suffrage and civil rights.

A detective foiled an assassination plot against Lincoln before his inauguration

In February 1861, detective Allan Pinkerton uncovered a plot to kill Abraham Lincoln en route to his inauguration. Lincoln secretly altered his travel plans and sneaked into Washington DC to take the oath of office. Pinkerton later founded the well-known Pinkerton's National Detective Agency.