With written authority from General Clinton, Tarleton and his men went quickly through Savannah and the surrounding territory and began to confiscate all the horses they could find. This was soon known, and their efforts were largely frustrated. Horses were inherently mobile, and their owners quickly hid them or rode them to isolated places outside the city. When the British army began moving slowly northward along the coast to initiate the attack, many of Tarleton’s dragoons were poorly mounted or still on foot. They fought two skirmishes on the way and were able to confiscate enough draft horses to mount themselves. Lord Cornwallis gave Tarleton a daunting task: close off all remaining access by the Americans to the mainland north of the Cooper River—their only chance for supplies, reinforcements, or eventual evacuation from the besieged city.

Even before General Clinton sailed from New York, George Washington had become deeply concerned about the prospective loss of Charles Town. He and his aides studied their best charts of the harbor and decided that a maximum effort should be made to prevent British ships from approaching the city. The Continental Congress was able to dispatch four frigates with 112 guns to report to General Lincoln for his defense. This squadron arrived late in December, and the French soon added two ships mounting 42 guns and South Carolina four ships with a total of 106 guns. The naval commander was Commodore Abraham Whipple, from Rhode Island. The primary military maneuvers were verbal sparring matches between the commodore and his own commanding general, and no effective plan was ever evolved to utilize the formidable firepower of the fleet.

A British force of three ships of the line and four frigates unloaded all their guns on barges and managed to cross the shallow bar offshore from Charles Town, then reloaded the artillery and entered the deeper channel that led to the city. Rather than face what he considered to be an invincible approaching foe, Commodore Whipple decided to move two of the American frigates to the inner harbor, transfer guns to shore batteries from the other ships, and then sink them all in an effort to block the channel and force the British vessels to sail close under the guns of Fort Moultrie in their approach to Charles Town. This is what the British did on April 8, and their fleet passed the shore batteries with only twenty-seven men killed or wounded and minimal damage to the seven ships. That same night, 750 American troops completed a five-hundred-mile march from Virginia, crossed the Cooper River, and joined Lincoln’s forces. There was great celebration among the local citizens as all the available southern troops were now assembled to defend their city.