Ft Sumter
Ft Sumter was a Federal fort located in the middle of Charleston Harbor in the South. The Confederates demanded that the Union vacate the fort, when they refused the Confederates attacked and the war was on.
The federal government had a number of forts and military installation in the South. As Southern states seceded, many of them were quickly turned over by state forces. One of the major exceptions was the federal facilities in and around Charleston. Federal troops there were concentrated in Fort Moultrie. In the middle of Charleston harbor sat Fort Sumter, unoccupied and still under construction. On November 15th Major Robert Anderson was named commander of Federal troops in Charleston. He quickly came to the conclusion that Fort Moultrie was not defensible. The unoccupied Fort Sumter was defensible as it was situated in the middle of the harbor surrounding by deep water.
http://www.historycentral.com/CivilWar/FtSumter.html
