[1] His biracial father, George deGrasse, was the presumed natural son of French admiral François Joseph Paul de Grasse.

His younger brother, John van Salee de Grasse, was a respected physician and member of the Massachusetts Medical Society.

He was promptly assigned to work as a missionary among the predominantly Black communities of Jamaica, Newtown, and Flushing in the Queens borough of New York City.

[7] DeGrasse spent his final days as a missionary in Kingston, Jamaica, where he contracted yellow fever and died on January 11, 1841, at the age of 27.

[1][2] His funeral in New York City featured massive turnout from white and black clergy and laypeople and a sermon by Bishop Onderdonk.