Fort Sumter, a fortification built on a sandbar in the harbor of Charleston, South Carolina. It was the scene of the first military action in the American Civil War. The original brick fort, begun in 1830, was unfinished in December, 1860, when Major Robert Anderson moved his 129 Regular Army men there from nearby Fort Moultrie. South Carolina had just seceded from the Union, and Anderson felt he could defend Fort Sumter more effectively than Fort Moultrie.

The fort soon was besieged by Confederate volunteers under General Pierre G. T. Beauregard. A relief ship, Star of the West, was driven out to sea by Confederate ships and shore batteries. On April 12, 1861, Beauregard began bombarding the fort, and it surrendered April 13. Fort Sumter was attacked twice, without success, by Union forces in 1863. The Confederates held the fort until the approach of General William T. Sherman's Union army in February, 1865, caused them to abandon it. In 1948 Fort Sumter was made a national monument.