American Civil War Begins
Confederate forces fired on Fort Sumter, starting the US Civil War
April 12, 1861
A Nation Tears Itself Apart
The American Civil War began on April 12, 1861, when Confederate forces opened fire on Fort Sumter, a U.S. military installation in the harbor of Charleston, South Carolina. After a 34-hour bombardment, the Union garrison surrendered and evacuated the fort. No one was killed in the bombardment itself, though two Union soldiers died in an accidental explosion during the surrender ceremony. The attack on Fort Sumter was the culmination of months of escalating tension following the election of Abraham Lincoln in November 1860. Seven Southern slave states had seceded from the Union and formed the Confederate States of America even before Lincoln was inaugurated on March 4, 1861.
The Road to War
The fundamental cause of secession and the war was slavery. Southern states depended economically on enslaved labor and feared that Lincoln's Republican Party, which opposed the expansion of slavery into new territories, would eventually threaten slavery where it already existed. Lincoln had won the presidency without carrying a single Southern state. The deep incompatibility between a society built on enslaved labor and one moving toward free labor had created a political crisis that decades of compromise had failed to resolve. The attack on Fort Sumter galvanized Northern public opinion. Lincoln called for 75,000 volunteers, and four more Southern states seceded and joined the Confederacy.
The Stakes of the Conflict
Both sides expected the war to be short. They were badly wrong. The Civil War lasted four years and killed an estimated 620,000 to 750,000 soldiers from both sides, making it by far the deadliest conflict in American history. Civilian deaths and the destruction of Southern infrastructure added enormously to the human cost. The war settled two fundamental questions that had haunted the republic since its founding: that the United States was one indivisible nation, and that slavery would be abolished. Use the date calculator to explore the span from Fort Sumter to the end of the war.