The Charles Town city fortifications were protected by a wide moat, eight feet deep, fed by a small stream and kept full of water by retaining dams. The primary target of the sappers was to breach these dams so the moat would drain and permit the attackers to use it as their final parallel trench. Despite the utmost concentration of musket, grape, and mortar fire on the British, this goal was reached on May 6, almost a month after Clinton had first demanded the surrender of the city. Three days later, they began a heavy bombardment, and perforated rounds filled with burning materials set fire to several houses. The Americans issued an official protest, and a British admiral’s aide sent an unauthorized note to the gunners: “The admiral and I begs their compliments to you and begs you will burn the Town as soon as possible, and send 24-pound shot into the stomacks of the women to see how they will deliver them.” The insulting message was widely quoted on both sides, and General Clinton apologized and stopped the bombardment, stating to his subordinates, “It is absurd, impolitic, and inhuman to burn a town you mean to occupy.”

General Lincoln was relieved that the flurry of smallpox cases had dissipated, but he was faced with a much more serious and immediate dilemma: whether to stay and defend the city or save what was now the only American army in the south. Lachlan McIntosh insisted that the troops be moved across the Cooper River immediately, but the lieutenant governor and other political leaders objected strenuously, aroused the other occupants of the city, and threatened to destroy all the boats and open the city’s gates to the enemy. Lincoln decided to postpone a decision, but within a few days the question was moot, as the British cavalry went into action.

Two weeks after the siege was begun, Lieutenant Colonel Banastre Tarleton made plans to cross the Cooper River. He received word that the main American force responsible for protecting Charles Town’s supply routes was stationed at Monck’s Corner, thirty miles due north of the city. Joined by Major Patrick Ferguson and his Tory troop, called the American Volunteers, Tarleton decided to attack. Moving rapidly at night and in complete silence, the British force located the Americans, commanded by General Isaac Huger. Although the Americans were preparing to march, they were completely surprised by the assault and offered little opposition as they fled through the swampland. Fourteen Americans were killed, nineteen seriously wounded, and sixty-four captured, along with fifty wagonloads of weapons, ammunition, and supplies destined for Charles Town. Tarleton’s prize possession was enough trained horses to replace the embarrassing mounts on which he had joined the battle.