Significance of Fort Mifflin and Fort Mercer
The Americans ultimately lost the battle for Fort Mifflin. The battle for Fort Mercer was a devastating defeat for the Hessians employed by the British, but ultimately the Americans evacuated the fort and left the site to the British. Much is made of the significance of the battles for these forts and Fort Mifflin is sometimes referred to as ““The Fort that Saved America.” https://hsp.org/blogs/history-hits/the-fort-that-saved-america
Joseph Plumb Martin, who endured the bombardment at Fort Mifflin, was quite bitter about what he felt was the lack of appreciation of what happened there:
I was at the siege and capture of lord Cornwallis, and the hardships of that were no more to be compared with this, than the sting of a bee is to the bite of a rattlesnake. But there has been but little notice taken of it; the reason of which is, there was no Washington, Putnam, or Wayne there. Had there been, the affair would have been extolled to the skies. No, it was only a few officers and soldiers who accomplished it in a remote quarter of the army. Such circumstances and such troops generally get but little notice taken of them, do what they will. Great men get great praise, little men, nothing.[1]
While Martin was not at Fort Mercer, he also resented what he thought was a failure to properly recognize the significance of that battle:
[At Fort Mercer] was fought as brilliant an action as was fought during the revolutionary war, considering the numbers engaged, Bunker-hill “to the contrary notwithstanding.” . . . [W]hy it has not been more noticed by the historians of the times I cannot tell.[2]
It was believed at the time that holding the forts just a little longer might have caused the British to abandon Philadelphia. Thus, General Varnum told General Washington, the day before Fort Mifflin fell:
The enimy are greatly discouraged by the forts holding out so long and it is the general opinion of the best of the citizens that the enemy will evacuate the city if the fort holds out until the middle of next week.[3]
But the fort was unable to hold out under the devastating bombardment and was abandoned on the evening of November 15 (see [insert link).
The argument is made that, by diverting the attention of the British in Philadelphia during October and November of 1777, the defense of these forts saved the Continental army, shattered by its losses at Brandywine, from an immediate pursuit by the British Army that might have resulted in the Americans’ inability to hold on and, after the terrible winter of Valley Forge, continue to fight through the war. That is a reasonable argument but, frankly, no one can know.
Certainly, the British had losses in their attack on Fort Mifflin, including the loss of two warships, one a large one. But the British Navy, aided by land artillery, did prevail and open the way to resupply the British Army in Philadelphia by the river route.
Questions about the significance of the victory at Fort Mercer also require some speculation. One obvious point is that a not insignificant number of Hessian soldiers, brought to America at considerable expense by the British crown, were dead or wounded at the end of the day and would no longer be able to fight for the British cause. Such a loss of manpower was an important issue for the British Army. It has also possible that the loss at Fort Mercer, when combined with the capture of Hessians at Trenton the previous year, caused the British commanders to conclude that Hessian armies could not be trusted without direction from on-site British commanders. Whether or not that is true, historians can debate. It is interesting to note that, when the British abandoned Philadelphia to return to New York the following spring, the Hessians were loaded on ships for transport while the British Army made its way by land across New Jersey. The land route was most likely to result in a confrontation with American forces, and it did, the significant if inconclusive battle with the Continental army at Monmouth Courthouse along the way.
One historian of the American Revolution, who focused on the war from the point of view of the British military, identified five important factors in the challenge that the British faced: the need to avoid any significant losses that would encourage the Patriot cause, a limit on the number of soldiers available that meant that losses even in victories had to be avoided, logistical difficulties in supplying their troops in America, problems in determining where the enemy was and what it was doing, and topography that favored defensive operations.[4] All of these factors came into play in the battles for the river forts.
As noted, the British did ultimately prevail in the battles of the river forts. This can be seen as a testament to the skill, courage, and creativity of what was, at that time, a very professional military force (both army and navy) in the face of challenging circumstances. But the resistance of the American patriots must also be honored. The Americans, of course, ultimately prevailed in the war itself, and that victory was the result of the determination, and willingness of American soldiers to risk all and to bear unbearable hardships, of which the river defenses are a shining, if now largely forgotten, example.
[1] Martin, J.P., The Adventures of a Revolutionary Soldier (1830), pg. 70, https://en.wikisource.org/wiki/The_Adventures_Of_A_Revolutionary_Soldier
[2] Id., pgs 61-62.
[3] “To George Washington from Major General Nathanael Greene, 14 November 1777,” Founders Online, National Archives, https://founders.archives.gov/documents/Washington/03-12-02-0238
[4] Spring, M.H., With Zeal and With Bayonets Only: The British Army on Campaign in North America, 1775-1783, pages 24-49