On December 26, 1860, six days after South Carolina seceded from the Union, U.S. Army Major Robert Anderson abandoned the indefensible Fort Moultrie, spiking its large guns, burning its gun carriages, and taking its smaller cannon with him to be trained on the city. He secretly relocated companies E and H (127 men, 13 of them musicians) of the 1st U.S. Artillery to Fort Sumter on his own initiative, without orders from his superiors. He thought that providing a stronger defense would delay an attack by South Carolina militia. The fort was not yet complete at the time and fewer than half of the cannons that should have been available were in place, due to military downsizing by President James Buchanan.
In a letter delivered January 31, 1861, South Carolina Governor Pickens demanded of President Buchanan that he surrender Fort Sumter because “I regard that possession is not consistent with the dignity or safety of the State of South Carolina.” Over the next few months repeated calls for evacuation of Fort Sumter from the government of South Carolina and then from Confederate Brigadier General P. G. T. Beauregard were ignored. Union attempts to resupply and reinforce the garrison were repulsed on January 9, 1861 when the first shots of the war, fired by cadets from the Citadel, prevented the steamer Star of the West, hired to transport troops and supplies to Fort Sumter, from completing the task.
After realizing that Anderson’s command would run out of food by April 15, 1861, President Lincoln ordered a fleet of ships, under the command of Gustavus V. Fox, to attempt entry into Charleston Harbor and supply Fort Sumter. The ships assigned were the steam sloop-of-war USS Pawnee, steam sloop-of-war USS Powhatan, transporting motorized launches and about 300 sailors (secretly removed from the Charleston fleet to join in the forced reinforcement of Fort Pickens, Pensacola, FL), armed screw steamer USS Pocahontas, Revenue CutterUSRC Harriet Lane, steamer Baltic transporting about 200 troops, composed of companies C and D of the 2nd U.S. Artillery, and three hired tugboats with added protection against small arms fire to be used to tow troop and supply barges directly to Fort Sumter. By April 6, 1861, the first ships began to set sail for their rendezvous off the Charleston Bar. The first to arrive was Harriet Lane, the evening of April 11, 1861.