[1] The family became part of the free people of color in Washington, D.C., before the Civil War.

[3] Considered part of the elite of African-American society, the Syphax family gained early advantages by their being freed before the war, and by Mariah Syphax being granted 17 acres of land at Arlington by her father Custis.

That land later was acquired by the government to become part of Arlington National Cemetery.

[a] Mary Custis (1808–1873), Mariah's white half-sister, married Robert E. Lee (1807–1870), who became a Confederate general when the Civil War broke out.

[5] Mariah and Charles had ten children, several of whom achieved important political positions from the 1850s onward.