The flag
The flag that flew over Fort Mifflin was not the “star spangled banner” that, in later years, survived a different bombardment and inspired the United States’ national anthem.[1] The flag in use at the time had stripes but not stars. As shown above, that flag has been recreated to fly over existing ruins at Fort Mifflin.
The flag that flew over Fort Mifflin served at least two purposes. Most importantly, it signaled to those attacking the fort that the fort was still being actively defended by the Americans. The flagpole was also used, however, as a means to signal the “galleys” of the Pennsylvania Navy, boats with cannons, that were supporting the effort to block the river.
This contemporary drawing of the fort shows the flag as flying high above the fort. If you look closely, you can see that the flagpole was supported by, and the flag was thus accessible by climbing, the type of rigging that accompanies a ship’s mast, of which the pole may have been made.
View of Mud Island before its reduction, 16th Novr., 1777, under the direction of John Montresor, Esqr., chief engineer in America, taken from the dyke in front of the six gun battery on Carpenter’s Island, https://www.loc.gov/pictures/resource/ppmsca.23163/
Joseph Martin, in his memoir, recounts an incident relating to the flag that might have ended his life there, and did end the life of a fellow defender:
In the height of the cannonade it was desirable to hoist a signal flag for some of our gallies, that were lying above us, to come down to our assistance. The officers inquired who would undertake it; as none appeared willing for some time, I was about to offer my services; I considered it no more exposure of my life than it was to remain where I was; the flagstaff was of easy ascent, being an old ship’s mast, having shrouds to the ground, and the round top still remaining. While I was still hesitating, a sergeant of the Artillery offered himself; he accordingly ascended to the round top, pulled down the flag to affix the signal flag to the halyard, upon which the enemy, thinking we had struck, ceased firing in every direction and cheered. “Up with the flag!” was the cry of our officers in every part of the fort. The flags were accordingly hoisted, and the firing was immediately renewed. The sergeant then came down and had not gone half a rod from the foot of the staff, when he was cut in two by a cannon shot. This caused me some serious reflections at the time. He was killed! had I been at the same business I might have been killed; but it might have been otherwise ordered by Divine Providence,—we might have both lived,—I am not predestinarian enough to determine it.[2]
We know of the existence of Joseph Martin only because he wrote his memoir. We have no certain information about who was the sergeant who died, but a blog reporting second hand a flyer distributed by the Fort authorities at some point says that the sergeant who gave his life at the flagpole was named Andrew Mackemson and that his brother James, a lieutenant, was also killed in re-raising the flag.[3] When visiting the fort today we do not know with certainty where the flagpole was, though the drawing of the fort by British Captain Montressor shows the flag near the center of the fort.
When the Americans did eventually abandon the Fort, they left their flag flying, both as an indication that they were not surrendering and, likely, in an attempt to avoid a land attack on the fort during their last retreat.
[1] An interesting footnote is that Colonel Smith, who commanded Fort Mifflin and survived the intense bombardment there, later was in overall command of the defenses of Baltimore during the War of 1812. Part of those defenses was Fort McHenry, where the star-spangled banner of the anthem could, after the British bombardment of that fort, be seen in the “dawn’s early light.”
[2] Martin, J.P., The Adventures of a Revolutionary Soldier (1830), pg. 67, https://en.wikisource.org/wiki/The_Adventures_Of_A_Revolutionary_Soldier
[3] https://wandering-through-time-and-place.com/2017/01/29/fort-mifflin-a-tale-of-death-heroism-and-a-flag/