Born free in Virginia, he served as a justice of the peace of the Arlington Magisterial Board.
His mother was the natural daughter of an enslaved woman, Ariana Carter, and white planter George Washington Parke Custis.
Custis permitted his mixed-race daughter and her chosen spouse, Charles Syphax, to marry at his mansion of Arlington in 1821.
[1] In addition, Custis arranged in 1826 for Maria Syphax and her (then) two children to be freed by selling them to a Quaker apothecary.
He died in Brooklyn, New York, on September 8, 1916, and was buried in Cypress Hill Cemetery in that city.