This Day in History: The failed British attack on Fort Mifflin
On this day in 1777, the British try to drive Americans away from Fort Mifflin. They failed. Americans held their own against six British warships.
General Howe was then in Philadelphia, close to the Delaware River. The British had seized the American capital on September 26. It should have been a huge victory for Howe, but it wasn’t exactly working out that way. He had one big problem on his hands: How would he get supplies?
Overland routes to the city were not feasible because George Washington’s army still had control of much of the land around Philadelphia. Instead, Howe needed to find a way to wrest control of the Delaware from Americans. That meant driving them out of the forts that they held along the river—but especially Forts Mifflin and Mercer! Those two forts faced each other, one on each side of the Delaware. The British also had to get past several chevaux-de-frise (weapons composed of sharp spikes) that Americans had submerged in the water.
Even before Howe marched into Philadelphia, Washington saw that Howe would face these difficulties. He wrote to the President of Congress: “Genl Howe’s Situation in Philadelphia will not be the most agreeable; for if his supplies can be stopped by Water, it may be easily done by land. To do both, shall be my utmost endeavour, and I am not yet without hope, that the acquisition of Philadelphia may, instead of his good fortune, prove his Ruin.”
Howe and his brother, Admiral Howe, decided to launch a two-pronged attack. First, a detachment of Germans attacked Fort Mercer on October 22. They found the fort better fortified than they had expected. Although they managed to get into one part of the fort, they soon discovered that they were in a section that had been deliberately abandoned. They were trapped, with Americans firing relentlessly at them. The Germans soon retreated, having lost one-third of their force.
The next day, the planned attack on Fort Mifflin began. Admiral Howe planned to send one warship, HMS Vigilant, around Fort Mifflin, to the west, where the fort was more vulnerable. Five other warships would act as a distraction on the east. This attack ran into trouble, too! Three of the ships ran aground, at least in part due to the submerged chevaux-de-frise. In the meantime, Americans and British were pummeling each other with their artillery. The British were unable to get their ships back afloat in the midst of the heavy fire and two of their ships, HMS Augusta and HMS Merlin, ended up catching fire and exploding.
The battle lasted for two days, but in the end, Americans remained in possession of Fort Mifflin. The victory was important. All of these efforts helped to buy Washington’s army more time to move into winter quarters at Valley Forge.
Unfortunately, the British did not give up, and they would soon make another attempt to drive Americans from their fort. Stay tuned for part two of the story in a few weeks.
Henry W. Harrison, Battles Of The Republic, By Sea And Land, from Lexington to the City of Mexico (1858)
Jeffery M. Dorwart, Fort Mifflin of Philadelphia: An Illustrated History (1998)
Letter from George Washington to John Hancock (Sept. 23, 1777)
Stephen R. Taaffe, The Philadelphia Campaign, 1777-1778 (2003)
The City Of Mexico (1858) (reprint available HERE)