Commemorating the battle
While many died at Fort Mercer, at Red Bank, there were, proportionally, a large number of American survivors. See Fort Mercer–Timeline. Many of those fought through the war and some survived the entire conflict. There is a monument at the battlefield site that was raised 50 years after the battle in a ceremony attended by some who fought there. It is interesting to contemplate those survivors, by then old men, gathering to remember a few hours in 1777 that had prematurely ended the lives of some of their comrades and so many of their enemies. This is a picture of what may be either the monument or its replacement:
It is reported by a 19th century visitor that the original inscription on the monument to the effect that it was erected by Pennsylvania and New Jersey volunteers was later defaced, first by vandals obliterating the reference to Pennsylvania, and then, in apparent retaliation, by vandals obliterating the reference to New Jersey.[1]
This evidence of the less admirable traits of humankind was apparently matched later with the desecration of the stone marking the grave of General von Donop. While in a visit by a French veteran in 1781 refers to a stone with this short epitaph: ‘ Here lies buried Colonel Donop.’ “[2] by 1851 the stone marking the grave (which reportedly by that time had been robbed of its bones), was gone and a marker with much of its text obliterated was in its place.[3] There is a suggestion that whatever marking on that was left was further obliterated in later years, reportedly during anti-German sentiment in the time of World War I. In any case, there is no longer a marking of the grave of any type.
There is now a more modern tall monument in the middle of what was the part of the fort that the Americans defended. See Fort Mercer Today.
[1]The Pictorial Field-book of the Revolution Or, Illustrations, by Pen and Pencil, of the History, Biography, Scenery, Relics, and Traditions of the War for Independence, pg. 294, Benson John Lossing · 1851, https://www.google.com/books/edition/THE_PICTORIAL_FIELD_BOOK_OF_THE_REVOLUTI/Hb3IwPvn8AwC?hl=en&gbpv=1&bsq=mercer Assuming that that story is true, the monument was repaired, as the references to the two states can be clearly seen today. Or possibly it was replaced with another one that bears the same inscription, as the Lossing book describes it as being 15 feet high and the current monument seems shorter than that. The fact that the monument appears at different places on different post-battle maps of the site suggests that the monument may have been moved, see REPORT OF AN ARCHEOLOGICAL SURVEY AT RED BANK BATTLEFIELD PARK (FORT MERCER), NATIONAL PARK, GLOUCESTER COUNTY, NEW JERSEY, page 14, https://www.gloucestercountynj.gov/DocumentCenter/View/959/Red-Bank-Battlefield-Archeology-Report-PDF?bidId= , and, perhaps rather than being moved, it was replaced.
[2] Travels in North-America : in the years 1780-81-82, Chastellux, François Jean, marquis de, https://www.loc.gov/resource/lhbtn.06665
[3] The Pictorial Field-book of the Revolution Or, Illustrations, by Pen and Pencil, of the History, Biography, Scenery, Relics, and Traditions of the War for Independence, pg. 290, Benson John Lossing · 1851, https://www.google.com/books/edition/THE_PICTORIAL_FIELD_BOOK_OF_THE_REVOLUTI/Hb3IwPvn8AwC?hl=en&gbpv=1&bsq=mercer