Since dawn, the brigade of fewer than 1,000 men had held against a much larger attacking British force that had stolen a march in the night on the American position in Brooklyn. The Americans were part of Gen. George Washington's fast-crumbling defense of New York.
Units elsewhere had already retreated. And by midday, a second British force was advancing and closing all avenues of escape save one. The American brigade could surrender or risk fleeing across the still open marsh and creek, where they would surely become easy targets for British musket and artillery fire.
The brigade commander choose neither. He directed Maj. Mordecai Gist, a prominent Baltimore merchant, to lead his 400 Marylanders in a frontal assault against thousands of British and Hessian soldiers massed around the stone Cortelyou House.
Their first assault so surprised the British they were driven briefly from the house before recapturing it. Gist's men attacked again and again, almost reaching the British lines. On the sixth attempt, the Marylanders finally gave up and ran for the swamp, leaving 256 dead.
The British buried them in unmarked trenches. The Marylanders' attack enabled the rest of the brigade to slog across Gowanus Creek to rejoin Washington's temporary line near the East River. The British failed to press their advantage.
Two days later, Washington evacuated Long Island in a Dunkirk-style flotilla of small boats to Manhattan. And again, the Marylanders were deployed as part of an attack force to screen this escape.
By the turn of the century, when a monument was already erected in the Marylanders' memory in Prospect Park, the mounds of the common grave of the 256 men were still visible at what was then a coal yard, said Brooklynite Martha Willett, who has a century-old drawing of the mounds as they appeared at the time. But sometime early in this century, she said, buildings were built on the mounds, so that her generation could only imagine how the site once looked.