On April 10, 1861, Brigadier General Beauregard, in command of the provisional Confederate forces at Charleston, South Carolina, demanded the surrender of the Union garrison of Fort Sumter in Charleston Harbor. Garrison commander Anderson refused. On April 12, Confederate batteries opened fire on the fort, which was unable to reply effectively. On April 13, Major Anderson surrendered Fort Sumter, evacuating the garrison on the following day. The bombardment of Fort Sumter was the opening engagement of the American Civil War.