The Battle of Fort Sumter was the first military engagement of the American Civil War, occurring on April 12-13, 1861. Located in Charleston Harbor, South Carolina, the fort was held by Union forces under Major Robert Anderson. Tensions escalated after several Southern states seceded from the Union, leading to the Confederate forces demanding the fort's surrender. When Major Anderson refused, Confederate General P.G.T. Beauregard ordered an attack. After 34 hours of bombardment, Anderson surrendered the fort, marking a significant moment that ignited the conflict between the Union and Confederacy. This battle set the stage for four years of war.