Are you talking about this guy?
in the 1880 United States Federal Census
Or this guy?
in the New York State, Marriage Index, 1881-1967
My extended line has : Mynderse [middle name?] Dubois
Born about 1836 [uncertain] in Ulster County NY
Son of James P. Dubois and Margaret (Unknown) Dubois
Brother of John H. Dubois, Lorenzo Dubois and Charles Dubois [add sibling]
Husband of Abbie M. (Spencer) DuBois — married 1857 (to 1884) in Ulster County NY
Father of Kate DuBois, Libbie E. (DuBois) Sickly, Ida DuBois, John L H DuBois, Maggie (DuBois) Vanostrand, James H. DuBois, Charles DuBois, Anna DuBois and George DuBois [add child]
Died about 1884 [uncertain] in Ulster County NY
Profile manager: Daniel Brown [send private message]