Defending the fort—an integrated American army
Most of the defenders of Fort Mercer were men from two regiments of Continental troops from Rhode Island. These were integrated units.[1] Rhode Island enlisted African Americans, some free and some slaves (who would apparently be given their freedom if they survived the service) and also native Americans as well as whites. There has been dispute about how much of the Rhode Island force was African American at the time of the battle (and afterwards),[2] but it is indisputable and worth noting that African and native Americans served beside Americans of European descent in this significant American victory.[3]
For a description of the attack on the Fort, see Fort Mercer–Timeline.
[1] See Green, S.L., FREEBORN MEN OF COLOR: THE FRANCK BROTHERS IN REVOLUTIONARY NORTH AMERICA, 1755-1820 (2011), https://etd.ohiolink.edu/apexprod/rws_etd/send_file/send?accession=bgsu1300735596&disposition=inline (describing, inter alia, service of two African American brothers who were part of the regiments that defended the fort; the brothers were free men whose father had served in the French and Indian war).
[2]Popek, D.M., They “… fought bravely, but were unfortunate: ” The True Story of Rhode Island’s “Black Regiment” and the Failure of Segregation in Rhode Island’s Continental Line, 1777-1783 (2015), https://books.google.com/books?id=HMnyCgAAQBAJ&pg=PP107&lpg=PP107&dq=fort+mifflin+connecticut+8th+continental&source=bl&ots=1uk5PMlK7i&sig=ACfU3U1HY_IMfM5udou_kro0Eq7iCQ1_7A&hl=en&sa=X&ved=2ahUKEwirtdz5jLHzAhWRFVkFHf54DGwQ6AF6BAgfEAM#v=onepage&q&f=false
Popek reports that one of the Americans wounded during the attack was a man of color. Id.
It is interesting that the two surviving diaries from the Rhode Island regiment, one by an officer and the other by an enlisted man make no mention of the race of their colleagues, which may perhaps be taken as a suggestion that, in the shared rigors of the campaigns and the dangers of the firing lines, race was not a particular issue. “The Israel Angell Diary, 1 October 1777-28 February 1778,” Rhode Island History, Volume 58, Number 4 (2000), http://www.rihs.org/assetts/files/publications/2000_Nov.pdf ; Greenman, J., Diary of a Common Soldier in the American Revolution, 1775-1783: An Annotated Edition of the Military Journal of Jeremiah Greenman, edited by Bray, R. and Bushnell, P, (1978).
[3] It should probably also be noted that one of the two Americans executed for guiding the Hessian force to Fort Mercer was an enslaved African American. “The Israel Angell Diary, 1 October 1777-28 February 1778,” Rhode Island History, Volume 58, Number 4, note 33 (2000), http://www.rihs.org/assetts/files/publications/2000_Nov.pdf Again, Greenman noted the hanging in his diary entry for November 1, 1777, but made not mention of the races of those executed. Greenman, J., Diary of a Common Soldier in the American Revolution, 1775-1783: An Annotated Edition of the Military Journal of Jeremiah Greenman, edited by Bray, R. and Bushnell, P., pg. 83 (1978).