Fort Mifflin- timeline of the attack
The initial attempt to reduce Fort Mifflin was led by Captain Montresor, the British officer who had been responsible for designing the original fortifications, which had not been completed. He brought artillery onto Province Island, which was just across a relatively narrow channel from Mud Island on the Pennsylvania side. The Americans had tried to make Province Island unusable for attack by cutting a trench through beach areas the effectively flooded the island. The British repaired the breach and managed to get cannon onto the island, with which they started to bombard the fort.
Thomas Paine, the eloquent pamphleteer of the Revolution, personally made a short visit to Fort Mifflin in September and observed that the muddy conditions of the island were, at the outset, an advantage. In a letter to Benjamin Franklin, Paine made this explanation:
At Noon I went with Col. Greene, who commanded at Red Bank, over to fort Mifflin (Mud Island) the Enemy opened that day 2. two Gun Batteries and a Mortar Battery on the fort. They threw about 30 Shells into it that afternoon without doing any damage; the Ground being damp and Spongy not above five or Six Burst, not a Man was killed or wounded.[1]
Joseph Martin, a private who manned the fort but arrived later, had a similar experience:
In front of the barracks and other necessary places, were parades and walks, the rest of the ground was soft mud. I have seen the enemy’s shells fall upon it and sink so low that their report could not be heard when they burst, and I could only feel a tremulous motion of the earth at the time. At other times, when they burst near the surface of the ground, they would throw the mud fifty feet in the air.[2]
On October 9, 1777, the British had a battery in place on Province Island. The placement of the battery was contested by river galleys, who managed to inflict some casualties but could not prevent the installation of the cannon.[3]
By October 11, the British had many more guns and soldiers on Province Island and attempted to place cannon within musket shot of the Fort. This attempt was met by Americans firing from river boats and from the fort and led to the surrender of the British soldiers manning the cannon. While those soldiers were under the white flag of surrender, they were relieved by another British force, which was allowed to approach based on the understanding that it was also surrendering in light of the white flag. Instead, the new force rescued the British garrison, in what was considered a shocking breach of the laws of war at that time. Colonel Smith complained of this to General Washington, who perhaps complained to his British counterpart General Howe. There is a suggestion, in any case, that the British officer involved may have been court martialed for “for misbehaving before the Enemy” on that date.[4]
The next day, October 12, Lieutenant Colonel Smith, who commanded at Fort Mifflin, reported to General Washington that the Americans had made several attempts to storm the British works, losing soldiers killed and wounded, without success. The correspondence between him and General Washington included suggestions and discussion of renewed attempts to flood the island by breaching the high ground along the riverfront, but it is not clear whether that was ever accomplished.[5]
Meanwhile, the British expanded the scope of their artillery installations to include not only Province Island but neighboring Carpenters Island. The Americans apparently continued to attack the British emplacements where possible. A diary entry from October 19, 1777, recounts a successful attack by Colonel Smith from Fort Mifflin on the British works, supported by the river galleys. It is unclear whether this is simply a description at a later date of the October 11 attack described above. [6]
At this point, the part of the fort facing the British artillery was a wooden palisade with wooden block houses at each corner. This would provide cover for fire against an infantry attack, but the wooden palisades were a less good defense against cannon. General Washington sent a French officer and engineer, Major de Fleury, to the fort on October 14. He ordered improvement to the fortification, including earthworks on the side of the fort facing the British cannon. Under his direction, the garrison would build up in the evening what the British had knocked down during the day. As Private Martin described it: “the British batteries in the course of the day would nearly level our works; and we were, like the beaver, obliged to repair our dams in the night.”[7] There appear, during this time, also to have been efforts to bring replacement wooden palisades over from the New Jersey shore to replace what was destroyed by the British.
On October 16, General Howe visited the British artillery positions. Frustrated by the lack of success at that time, he ordered that heavier guns be brought up and that the navy also work its way up the river to join in the cannonade of the fort.[8]
As Colonel Smith made clear in his correspondence with General Washington, the garrison at the fort were in sad shape. They not only lacked shoes and socks, in many cases apparently they lacked pants as well.[9] Washington reinforced the fort with continental soldiers. Colonel Greene, who commanded at Fort Mercer, on the New Jersey side of the river, lead that effort. By October 20th, Colonel Angell of a Rhode Island regiment recently arrived at Fort Mercer reported that “the greatest part of my regiment” was at Fort Mifflin, having relieved troops of Colonel Greene, which had presumably been sent there earlier.[10]
At that time Jeremiah Greenwood, an enlisted man in Angell’s regiment, reported that, as a result of the bombardment, the two western blockhouses were “ruined” and “the north one blew up.”[11]
The troops from Fort Mercer soon had other problems to deal with, and Greenwood reports that they were brought back across the river on the morning of the 22nd just in time to assist in the defense of that fort (described in Fort Mercer–Timeline). It is reported that a force of grenadiers was on Province Island preparing to assault the fort by storm in concert with the attack on Fort Mercer. They were still seen on the 23d by Greenman— “part of the English army drew up in battle array on Province Island ready to th[r]o them selves into boats, to storm the Fort,”[12] But the attack on Fort Mercer was a disaster for the Hessian force employed by the British and the grenadiers were called off.[13]
On October 23, the British also lost two warships, one the mammoth Augusta, that had made their way through the Billingsport river obstructions with the intent of aiding the assault on Fort Mercer. The Augusta blew up after being fired on from Fort Mifflin and from American river vessels and the sloop Pearl was destroyed by the British because it had gone aground. See description at Fort Mercer–Timeline.
The Rhode Island regiments were part of a brigade commanded by General James Mitchell Varnum, and on October 29 General Washington put him in overall charge of Fort Mifflin and Fort Mercer. Varnum then sent two Connecticut regiments that were part of his brigade, the 4th and the 8th, to Fort Mifflin on November 3.[14] Private Joseph Plumb Martin, quoted elsewhere on this site, was part of the 8th and served through the rest of the siege. (Interestingly, Martin describes the destruction of the Augusta as being “[t]he first attempt the British made against the place after I entered it.”[15] Since Martin appears to have arrived after the battle at Fort Mercer, and the loss of the Augusta occurred the next day, his memory of events, in his memoir written many years later, may have been off. Alternatively, he might have been sent to Fort Mifflin before the rest of his regiment for some reason. There is no way to know.)
After his mid-October visit to Province Island, General Howe ordered a significant upgrade to the attacking forces. One part of that effort was to remove the obstacles that kept warships further downriver from Fort Mifflin. This was a line of chevaux-de-frise near Billingsport. The British had taken the fort guarding those obstacles (see Fort Billingsport) and they were to be cleared so that warships could approach Fort Mifflin and bombard it. This extract from a contemporary map shows this downriver line of obstacles, here referred to as “stackadoes,” apparently a term used by the Americans.
https://www.amrevmuseum.org/thaddeus-kosciuszko-virtual-walking-tour
The full map gives a sense of where they were (see the line of obstructions and group of ships) relative to Fort Mifflin:
The course of Delaware River from Philadelphia to Chester with the several forts and stackadoes raised by the rebels, and the attacks made by His Majesty’s land and sea forces. Faden, William, 1749-1836. George Barrie & Sons. London, W. Faden, 1785. Philadelphia. George Barrie & Sons, c. 1904, https://www.loc.gov/resource/g3792d.ct006434/
The second step taken by the British was to move much larger cannon to the Pennsylvania shore opposite Fort Mifflin. Four 32 pound cannon from the 74 gun man-of-war Somerset (later to take part in the bombardment itself, see below) were brought up on barges from downriver. Two were placed on high ground on Province Island and two on a floating battery on the Schuykill River. By November 9th, the British land forces had, in addition to those four massive cannon, six 24 pounders (brought upriver on barges from British warships), two 8 inch howitzers, an 8 inch mortar, and a 13 inch mortar all in two batteries on Carpenter’s Island. They also had, on Province Island, in addition to the cannon from the Somerset, two 12-pounders and one 18 pounder.[16]
The full cannonade began at 7:30 am on November 10. In the next few days, the fortifications were pummeled and destroyed, killing and wounding a number of American defenders, and wounding Colonel Smith, who was in command but had to be evacuated to New Jersey (as noted below, he reurned to the fort and reported on its condition before it was ultimately abandonned). General Varnum was as noted now in overall command of the river defenses in the area, but he and other officers were in constant contact with General Washington, who ultimately gave orders that reflected the value of holding the fort and also an understanding that men could not be asked to do the impossible. It is interesting to note that for several days after the beginning of the cannonade on November 10 General Varnum continued to assure Washington that only a few Americans were being killed each day. The American continued to resupply the fort with men and to rebuild, to the extent possible, what the British cannon destroyed.[17]
A sign at Fort Mifflin contains quotations from the diary of British Captain Montresor to the effect that the Americans in the fort did have some successes. He is reported as stating that the floating battery with two 32 pound cannon from the Somerset was deployed on November 12 close to the fort and fired on it for two hours, but it “was silenced by the Fort. Three shot went through her and one killed.”[18]
In a letter from Colonel Smith to General Varnum of November 12, which Varnum forwarded to Washington, Smith described the fort as being in a desperate situation, but thought it might be held with more men:
I am clearly of your opinion to keep the fort to the last extremity. which in my opinion may as well be done with 100 as 500 men. By tomorrow night every thing will be levelled—our block houses next the enemy are almost destroyed—the N. West Block has but one piece of canon fit for service—one side of it is entirely fallen down—they have begun on that next Read’s House & dismounted two pieces—the pallisades next the meadow are levelled; the small battery in front of the gate torn up—the 12 pound battery torn up also—The wall is broke thro’ in different places—In fine should they storm us I think we must fall—however even as it is your opinion I will keep the garrison tho’ I lose mine and my soldiers lives. . . . I except to see the whole of the N.W. Blockhouse fall every minute.[19]
Varnum informed Washington that the garrison could not hold out for more than two days,[20] though they ultimately did last one more day than he had predicted.
The British now found a way to bring more cannon close to the fort, ensuring its doom. As noted, Mud Island was separated from Province and Carpenter Islands by a narrow channel. On its other side was the deep channel, obstructed by chevaux-de-frise, that would if cleared permit large ships to sail up to Philadelphia. Those large warships could not come up on the Province/Carpenter island side because entry way from the main river to the channel was not deep enough. As seen on the map, below Mud Island was Hog Island and below that was a narrow channel that was apparently not very deep.
Detail from a 1777 map showing the locations of Fort Mercer (Red Bank) and Fort Mifflin (Fort Island). (Library of Congress), https://allthingsliberty.com/2018/08/a-visit-to-old-fort-mercer-on-the-delaware/
Having cleared the Billingsport obstructions sufficiently to get its large warships through, on the night of November 14, the British brought up several large ships, including the flagship Somerset, which, while still not able to sail directly across from the fort because of the upper river obstructions that the fort guarded, were close enough for their cannon to play upon the fort from an angle downriver.
Moreover, during the night of November 14, the British pulled a large ship, the Vigilant, which is described as a converted “East India merchant man,” and the gun-sloop Fury across the Hog Island bar during what is described as an unusually high flood tide and anchored them off Mud Island’s southwest corner.[21] While there were requests that the American river navy to approach and attack those ships, and its Commander Hazelwood reportedly ordered such an attack, the men of the navy apparently considered such a mission suicidal and declined.[22] Pennsylvania navy vessels, which were smaller and able to navigate shallower waters than the British, did come down on the other side of the river on November 15 to engage the large British ships there but were driven back with significant losses.[23]
This map gives a sense of how close those ships were to the Fort during the attack, and also shows where the other British ships involved with the attack were located. Note that the ships represented on the right side of the map on what appears to be shallower water presumably are the American river ships trying unsuccessfully to drive off or sink the British warships. For a description of those galleys, see The Pennsylvania Navy.
Credit: Wikimedia Commons described as Hessian Map of Delaware River Defenses, 1777, https://commons.wikimedia.org/wiki/File:HessianMapMudIsland.jpg
On November 15, the bombardment from all of these forces combined. Vigilant and Fury were now within pistol range of the southwest angle of the fort and fired broadsides into the Fort, dislodging the Americans’ last 32-pound canon. Moreover, British sailors in the rigging of the tall ship Vigilant were now able to fire down on soldiers in the fort and throw grenades into the fort to prevent soldiers from manning the cannon or rebuilding the defenses.[24]
General Varnum, who had downplayed the losses at the Fort an earlier reports to General Washington, in the afternoon of November 15 was very clear as to where things stood:
Fort Mercer [N.J.] 15th Novr. 1777, 6 oClk P.M.
Sir
The Firing is universal from the Shipping Batteries &c. We have lost a great many Men today, a great many of the Officers are killed and wounded. My fine Company of Artillery is almost destroy’d. We shall be obliged to evacuate the Fort this Night. I am your Excellency’s most obdt Servt
J.M. Varnum B.G.
Major Talbut is badly wounded, Major Fleury is wounded also. It is impossible for an Officer to possess more Merit than Major Thayer, who commands the brave little Garrison.[25]
That evening, the Americans abandoned Fort Mifflin, destroying anything that was left to destroy before leaving the island to the British.[26] See Escape.
There do not appear to be any clear records of the number of men killed and wounded at Fort Mifflin, during the months of the siege or during the last days, but the number seems clearly to be in the hundreds.
See Fort Mifflin and Fort Mercer: What was their significance?
[1] “To Benjamin Franklin from Thomas Paine: two letters, 16 May 1778,” Founders Online, National Archives, https://founders.archives.gov/documents/Franklin/01-26-02-0421 .
[2] https://play.google.com/books/reader?id=ZbdcAAAAcAAJ&pg=GBS.PA62&hl=en
[3] “To George Washington from Lieutenant Colonel Samuel Smith, 9 October 1777,” Founders Online, National Archives, https://founders.archives.gov/documents/Washington/03-11-02-0476 .
[4] “To George Washington from Lieutenant Colonel Samuel Smith, 11 October 1777,” Founders Online, National Archives, https://founders.archives.gov/documents/Washington/03-11-02-0497 . See note 2.
[5] “To George Washington from Lieutenant Colonel Samuel Smith, 12 October 1777,” Founders Online, National Archives, https://founders.archives.gov/documents/Washington/03-11-02-0503 .
[6] Greenman, J., Diary of a Common Soldier in the American Revolution, 1775-1783: An Annotated Edition of the Military Journal of Jeremiah Greenman, page 80, edited by Bray, R. and Bushnell, P. (1978). https://www.amazon.com/Common-Soldier-American-Revolution-1775-1783/dp/0875805280
[7] Martin, J.P., The Adventures of a Revolutionary Soldier (1830), https://en.wikisource.org/wiki/The_Adventures_Of_A_Revolutionary_Soldier
[8] Dorwat, J. M., Fort Mifflin of Philadelphia: An Illustrated History, pg. 39 (1998).
[9] “To George Washington from Lieutenant Colonel Samuel Smith, 14 October 1777,” Founders Online, National Archives, https://founders.archives.gov/documents/Washington/03-11-02-0519 .
[10] The Israel Angell Diary, October 1777-78, published in Rhode Island History, Vol. 58, No. 4, pg. 112, http://www.rihs.org/assetts/files/publications/2000_Nov.pdf
[11] Diary of a Common Soldier in the American Revolution, 1775-1783: An Annotated Edition of the Military Journal of Jeremiah Greenman, pg. 81. https://www.amazon.com/Common-Soldier-American-Revolution-1775-1783/dp/0875805280he
[12] Id.
[13] Dorwat, J. M., Fort Mifflin of Philadelphia: An Illustrated History, pg. 41 (1998).
[14] McGuire, Thomas J. (2007). The Philadelphia Campaign, Volume II. Mechanicsburg, 197, https://www.amazon.com/s?k=9780811749459&i=stripbooks&linkCode=qs
[15] Martin, J.P., The Adventures of a Revolutionary Soldier, pg. 64 (1830), https://en.wikisource.org/wiki/The_Adventures_Of_A_Revolutionary_Soldier
[16] Dorwat, J. M., Fort Mifflin of Philadelphia: An Illustrated History, pages 47-48 (1998).
[17] See generally corespondence between Washington and Varnum at https://founders.archives.gov/search/Correspondent%3A%22Varnum%2C%20James%20Mitchell%22%20Correspondent%3A%22Washington%2C%20George%22
[18] Captain Montresor’s journal can apparently be accessed by persons with particular permissions online or can be purchased in facsimile, but I have not personally checked the quotation on the sign.
[19] “To George Washington from Brigadier General James Mitchell Varnum, 11 November 1777,”note 2, Founders Online, National Archives, https://founders.archives.gov/documents/Washington/03-12-02-0206 .
[20] Id.
[21] Dorwat, J. M., Fort Mifflin of Philadelphia: An Illustrated History, pg.51 (1998),
[22] “To George Washington from Commodore John Hazelwood, 15 November 1777,” Founders Online, National Archives, https://founders.archives.gov/documents/Washington/03-12-02-0253 .
[23] Id., note 2, reporting his Commodore Hazelwood’s report that “we had on that Day 38 men Kill’d & Wounded & all the Galleys Except one much Shater’d with Shot” (PHarH: Records of Pennsylvania’s Revolutionary Governments, 1775–1790).
[24]Dorwat, J. M., Fort Mifflin of Philadelphia: An Illustrated History (1998), page 51
[25] “To George Washington from Brigadier General James Mitchell Varnum, 15 November 1777,” Founders Online, National Archives, https://founders.archives.gov/documents/Washington/03-12-02-0260 .
[26] Joseph Martin reports the following: “We left one man in the fort who had taken too large a dose of ‘the good creature.’ He was a deserter from the German forces in the British service. The British took him to Philadelphia, where (not being known by them) he engaged again in their service—received two or three guineas bounty, drew a British uniform, and came back to us again at the Valley Forge.” Martin, J.P., The Adventures of a Revolutionary Soldier, pg. 69 (1830), https://en.wikisource.org/wiki/The_Adventures_Of_A_Revolutionary_Soldier