His sister, Serena, married George T. Downing, who became a successful restaurateur, abolitionist, and African American civil rights activist.

Their later generations of descendants, who continued to "marry white", are said to include the Vanderbilts, the Whitneys, Jacqueline Kennedy Onassis, and Humphrey Bogart.

[7] Abraham was said to have also had a son in New York by a black mistress, establishing a line identified as African American while also having considerable European ancestry.

[7][3] Maria van Salee had married George de Grasse,[1] who was born in Calcutta as Azar Le Guen; he was of mixed-race, Indian-French ancestry.

[4] George de Grasse immigrated as a young man to the United States, settling in New York City by 1799.

[5] De Grasse worked for a period for Aaron Burr, who gave him two lots in the Five Points area of Lower Manhattan, making him a landowner as a free man of color.

Later that same year, he toured Europe and worked for a time as an assistant to French anatomist and surgeon Alfred-Armand-Louis-Marie Velpeau in Paris.

While his daily work often involved routine tasks like visits and prescriptions, his treatments included practices like bloodletting and inoculation during a smallpox epidemic in 1854.

His practice primarily catered to patients residing in the Fifth and Sixth Wards, areas with a historical significance as predominantly inhabited by Black communities.

"[9] Massachusetts governor John Albion Andrew awarded de Grasse a gold-hilted sword in recognition of his military service.

[9] After his discharge, de Grasse returned to Boston, where he died of unknown causes in 1868[2] and was buried at New York's Cypress Hill Cemetery.