As the British marched triumphantly into Philadelphia during the last days of September in 1777, a strategic dilemma faced General William Howe, commander of the army. Surrounded by rebel forces from the north, east and west, his troops were in desperate need of supplies—gunpowder, clothing, food, and munitions. Without these items the capture of Philadelphia might become meaningless and the British would be unable to pursue and destroy Washington’s Army before winter.
South of Philadelphia in the Delaware Bay sat a fleet British ships carrying the army’s much needed supplies. General Howe gave orders to sail the fleet up the river to provide new provisions to his occupying troops.
The Americans had secured a British built fortification, sitting on Mud Island, just below the city and across the river from New Jersey’s Fort Mercer in 1775. By the fall of 1777 approximately 200 men were garrisoned at this fort, now known as Fort Mifflin, charged with the duty of holding the British off “to the last extremity” so that Washington and his exhausted army could successfully move into winter quarters.
It was here, on the frozen, marshy ground within the walls of a stone and wood fort, the American Revolution produced a shining moment. Cold, ill and starving, the young garrison of (now) 400 men at Fort Mifflin refused to give up. The valiant efforts of the men at Fort Mifflin held the mighty British Navy at bay providing Washington and his troops time to arrive safely at Valley Forge where they shaped a strong and confident army. This battle escalated into the greatest bombardment of the American Revolution and one that many say changed the course of American history.
For nearly six weeks in the fall of 1777, American troops in Fort Mifflin and Fort Mercer frustrated British naval attempts to re-supply their occupying forces in Philadelphia. Early in the morning on November 10, 1777, the British took definitive action to reach Philadelphia via the Delaware. Daybreak brought a rain of cannon fire upon Fort Mifflin beginning the largest bombardment of the Revolutionary War.
Under the direction of French Major Francois de Fleury, an engineer and tireless worker, the Americans worked each night to repair the damage of the day.
On November 15th, finally clear after days of rain and high tides, the British sailed the Vigilant and the Fury, with nineteen cannon up the back channel to the west of Fort Mifflin. In the main channel of the Delaware three ships armed with 158 cannon anchored directly offshore of the fort, while to the east three additional ships armed with 51 cannon completed the naval assault.
Against this show of force, Fort Mifflin could respond with only ten cannon. It was reported that during one hour, 1000 cannon balls were fired at the fort. As the battle progressed, British Marines climbed to the crow’s nest of the Vigilant and threw hand grenades at the soldiers in the fort.
Exhausted, cold and out of ammunition, Major Simeon Thayer evacuated Fort Mifflin’s garrison to Fort Mercer with muffled oars after nightfall on November 15. Forty men remained at the fort and set fire to what was left before making their way across the Delaware to join their comrades. They crossed to New Jersey around midnight leaving Fort Mifflin ablaze, but the flag still flying.
A British officer remarked, “the behavior of the enemy…did them honor, nor did they quit the place ‘till their defenses were ruined, and the works rendered to rubbish, setting the works in a blaze when they could defend it no longer.”