Fort Sumter was a fortified federal facility whose purpose was to guard the mouth of Charleston harbor. The fort boasted walls eight to 12 feet thick and 50 feet high.By 1861 Fort Sumter was in some disrepair and meagerly manned, but was one of two major federal installations in the South that had not been taken over by Confederate forces. The commander, Major Robert Anderson, had sent word to Washington that supplies were running low.The political leaders on both sides faced a dilemma.Jefferson Davis was not anxious to move against Fort Sumter or Fort Pickens (at Pensacola, Florida). This caution angered radical Southerners.Abraham Lincoln also wanted to move with caution. The onus for firing the first shot would rest on the South.Lincoln informed South Carolina authorities that he was dispatching a ship carrying food, not arms. The Civil War had begun.Lincoln commenced mobilization by summoning militia forces and putting out a call for volunteers. A blockade of Southern port cities was proclaimed.Before the end of May the states of Virginia, Arkansas, Tennessee and North Carolina joined the Confederacy, bringing the total number of seceded states to eleven.