The two most notable exceptions to these seizures were the forts at Pensacola, Florida, and Charleston, South Carolina. They, along with only two other installations, which were located in the Key West region of Florida, remained in federal hands. At Pensacola Harbor, federal property consisted of a Navy Yard, two forts on the mainland, a military barracks, and Fort Pickens. Fort Pickens stood at the western edge of an island, running roughly parallel to the coastline and separated from it by Pensacola Bay. On January 10, 1861, the same day as Florida seceded from the Union, the small federal contingent at Pensacola took steps to defend federal property. Lieutenant Adam J. Slemmer, in charge of army troops and acting under authority from Washington, transferred his command from the mainland to Fort Pickens, a more defensible position, which provided relative easy reinforcement from the Gulf of Mexico. Two days later, Florida and Alabama troops took over all the mainland posts, but failed to dislodge the federal presence at Fort Pickens. Towards the latter part of January, reinforcements commanded by Captain Israel Vogdes were sent to the fort aboard the U.S.S. Brooklyn, a powerful steampowered warship. Additional naval support was also sent to Pensacola, including the recently built sailing frigate, the U.S.S. Sabine. Although these vessels arrived safely, the Brooklyn landed only provisions, not troops, at the fort. The explanation for this change of policy was an arrangement, or "truce," entered into by President Buchanan and Florida officials, by which Florida agreed not to attack the fort and, in return, the Brooklyn would not land its troops unless the fort were attacked or preparations made for its attack. Thus an uneasy standoff existed at Fort Pickens, as the South put increasing military pressure on the fort, while a considerable Union military presence remained close by.
Meanwhile, at Charleston Harbor, a similar situation existed at Fort Sumter. Like Fort Pickens, Sumter was located offshore, being constructed on an artificial island made from the granite of northern quarries. Nearby fortifications, such as Forts Moultrie and Johnson, and Castle Pinckney, virtually surrounded it. Prior to South Carolina's secession on December 20, 1860, the Buchanan administration declined to reinforce the small federal contingent largely housed at Fort Moultrie, and ordered its commander, Major Robert Anderson, to defend the forts if attacked but not to provoke hostilities. After December 20, Anderson's situation became more difficult. With public sentiment pressing for action, South Carolina sent commissioners to Washington to negotiate the transfer of the forts to the state, and requested immediate control of Fort Sumter. Like Slemmer, Anderson considered his situation increasingly precarious, indeed untenable if South Carolina occupied Sumter. After nightfall, on the evening of December 26, Anderson moved his small force from Moultrie to the more defensible Sumter.
Despite South Carolina's insistence that Anderson's action was a hostile act and must be repudiated, President Buchanan refused to order Anderson to return. South Carolina then proceeded to occupy federal property in Charleston, including the military posts surrounding Sumter. By January 1, only Sumter remained a Union outpost in the midst of secessionist South Carolina. Stiffening his resolve to protect Anderson's vulnerable garrison, President Buchanan approved an expedition headed by a chartered merchant steamer, the Star of the West, to resupply and reinforce Fort Sumter. On January 9, 1861, the ship arrived at Charleston Harbor, but turned back when it was fired upon by South Carolina's batteries. Despite the outbreak of fighting, war did not ensue. As at Pensacola, a precarious truce went into effect in Charleston Harbor. The Confederate government, which assumed responsibility for Sumter after its establishment, tightened the noose around the fort, while the Union garrison continued to hold firm. The situation at Sumter received considerably more public attention, both in the North and the South, than that at Pickens. It rapidly became a symbol of rival definitions of sovereignty and honor.