Fox's plan to relieve Fort Sumter was a straightforward one. He proposed to anchor three small warships off Charleston Harbor near the entrance to Swash Channel, about four miles from the beleaguered fort. To avoid the obstructions at the harbor's entrance, soldiers and provisions would be transferred from a large, oceangoing steamer to small, armed launches that would be towed to Fort Sumter by three steam tugs that were to accompany the expedition from New York.

Fox's plan was not without risk. To reach Fort Sumter, the launches and tugs had to pass within 1,300 yards of the Confederate batteries on nearby Morris and Sullivan's islands. Moreover, Fox believed that the failure of Star of the West's expedition made his own task even more difficult. The Southerners, he felt, would have surely taken precautions to prevent a similar attempt to relieve Fort Sumter. "Since the repulse of the steamer Star of the West at Charleston it may be assumed that all channels over the bar are obstructed," Fox wrote. Nonetheless, he remained optimistic that the boats and light-draft tugs could avoid such obstacles. "As the bar is more than four miles in length," said Fox, "the spaces between these channels are too extensive to be closed."

Fox's plan met with enthusiastic approval from his civilian friends. He first explained his plan to George W. Blunt of New York. Convinced of its prospects for success, Fox and Blunt then enlisted the aid of Charles H. Marshall, who agreed to furnish and provision the necessary vessels without arousing suspicion.

The response of Federal authorities in Washington to Fox's plan was less enthusiastic. In February, Fox was called to Washington to explain the plan to Scott, who reported upon it favorably. In the end, however, the plan was rejected because Buchanan's administration decided to take no action to relieve Fort Sumter. The plan was better received, however, by advisers of President Lincoln, who was inaugurated on March 4, although they, too, initially rejected it. Scott now worried that the increased number of Southern batteries erected at Charleston since February made the plan impractical. But the initiative and daring of Fox's scheme impressed the new president. On March 19, 1861, Fox was dispatched to Charleston to visit Fort Sumter. "Our Uncle Abe Lincoln has taken a high esteem for me," Fox wrote to his wife, "and wishes me to take dispatches to Major Anderson at Fort Sumter with regard to its final evacuation and to obtain a clear statement of his condition which his letters, probably guarded, do not fully exhibit."

The trip gave Fox the opportunity to observe firsthand the situation at Fort Sumter. Upon his return to Washington, he finally won over those who were skeptical of his plan. With the help of Commodore Silas H. Stringham, the Navy Department's detailing officer, Fox finally convinced Lincoln of the rescue plan's viability. On March 30, the president dispatched Fox to New York with instructions to prepare for the voyage to Charleston.

During the preceding months, Fox had endured seemingly endless delays. Now, with the authorization in hand to proceed with the mission, he was forced to mount his relief expedition in great haste. In all, Fox had only nine days to assemble and prepare his force to sail.

Some of the preparations were completed with relative ease. Fox immediately engaged the services of the large civilian steamer Baltic to carry the bulk of his expedition. Other elements of Fox's plan did not come together so easily, however. The Navy had placed all its commissioned ships in the Atlantic waters at Fox's disposal, ordering the naval warships Powhatan, Pocahontas and Pawnee and the revenue cutter Harriet Lane to be placed "in readiness for sea service." Preparing the naval warships for the mission, however, proved no easy task. The 2,415-ton side-wheel steamer Powhatan, for instance, had already been decommissioned at the Brooklyn Navy Yard and her crew transferred to the receiving ship North Carolina by the time orders arrived for the vessel to join Fox's force. Crew members with less than a year remaining on their enlistments were expecting to be discharged, and many of the officers had already departed on leave. The demands of Fox's mission, however, meant that all leaves, transfers and discharges were canceled, and all crew members were ordered to return to the ship.

Hiring the tugboats for the mission proved to be the most difficult task of all for Fox. Because obvious danger surrounded the endeavor, Northern shipowners were reluctant to lend their tugs to the cause. Only the payment of the most "exorbitant rates," Fox complained, finally secured the services of three tugs--Yankee, Uncle Ben and Thomas Freeborn.

Other problems also plagued Fox's preparations. The quality of the troops provided by the U.S. Army for the mission left something to be desired. Fox later complained that the soldiers were "totally unfit to be thrown into a fort likely to be attacked by the rebels."

Fortunately for Fox, obtaining supplies to provision Fort Sumter was a simpler task. He found a staunch supporter in Major Amos B. Eaton of the Commissary Department, who "thanked God that an attempt was made to relieve Major Anderson's command" and "immediately provisioned for all contingencies."

Finally, when all preparations for Fox's mission were complete, the various vessels sailed for Charleston. Each made its way south separately. On April 6 the frigate Powhatan, under the command of Captain Samuel Mercer, prepared to sail from New York. Other vessels, including the revenue cutter Harriet Lane and tugs Uncle Ben and Yankee, soon made their way south. The sloop of war Pawnee, under the command of Commander Stephen C. Rowan, sailed from Norfolk, Va., on April 9. Baltic, with Fox on board, dropped down to Sandy Hook at the mouth of New York Harbor on the evening of April 8 and put out to sea the following morning.

Almost from the beginning, the weather played havoc with the carefully laid plans. Soon after the steamer Baltic sailed, a heavy gale set in, badly scattering the expedition's vessels and delaying the arrival of Fox's force. When Baltic arrived at Charleston at 3 a.m. on April 12, only Harriet Lane had completed the voyage. By 6 a.m., Pawnee joined the force, but her orders limited her usefulness. Fox boarded the vessel to ask Commander Rowan to stand in toward shore, but the captain could not comply because his orders required him to remain 10 miles east of the lighthouse and await Powhatan's arrival. Meanwhile, the Confederates had opened fire on Fort Sumter at 4:30 a.m. on April 12.

Bad weather was not the only problem plaguing Fox's mission. Complications with her owners prevented the tug Thomas Freeborn from ever sailing from New York. Another tug, Uncle Ben, did sail from New York, only to be seized by the Confederates after the gale drove her to seek shelter at Wilmington, N.C. Of the tugs, only Yankee reached Charleston Harbor, and even her arrival was delayed by rough weather.

Poor communications in Washington proved to be the biggest obstacle to Fox's plan. Fort Sumter was not the only Federal-held fort in Southern territory that was threatened by the Confederates. The strategically vital forts along Florida's Gulf Coast--Fort Taylor at Key West, Fort Jefferson in the Dry Tortugas and Fort Pickens at Pensacola--also required Federal attention. To support those forts, a relief expedition similar to Fox's was being fitted out under the command of Navy Lieutenant David D. Porter. Secretary of State William H. Seward, without the knowledge of Secretary of the Navy Gideon Welles, had obtained Lincoln's authorization to divert Powhatan to the gulf expedition. Just as she was preparing to sail from New York on April 6, Powhatan was ordered to leave the Charleston expedition and was sent to sea as part of the expedition to the Gulf of Mexico.

Powhatan's transfer had a devastating impact on Fox's mission. The Northern warship carried the armed launches and crews necessary to land troops and supplies from Baltic. To make matters worse, Fox did not learn of Powhatan's diversion until April 13, a week after it had taken place.