A fort at the entrance to the harbor of Charleston, South Carolina; the location of the first military engagement of the Civil War. In April 1861, several months after South Carolina had declared its secession from the United States, the militia of South Carolina demanded that the commander of the fort surrender. He refused, and the South Carolinians fired on the fort. There were no deaths in the incident. In response, however, President Abraham Lincoln called for volunteers to put down the “insurrection,” and the American Civil War began.