The American Civil War is also sometimes called the War Between the States. It began in 1861, when Southern states seceded from the Union, forming the Confederacy. The primary drive behind the secession was over slavery, and particularly the legality of slavery in new territories as the United States expanded westward.

The Civil War lasted four years and resulted in over 600,000 deaths. President Abraham Lincoln's adept leadership during this grisly period in American history has established him as one of the greatest political figures in history.