Researching McMullen ancestrry

William George McMullen was born Sep 1855, in Fayette County GA(according to LA death record). No father's name shown on death certificate, mother listed as Elisa.

William died 1930 in Dubach LA.

By 1880 census of Henry County GA, his mother, Elisa, b ~1837, GA, was living with William, as a widow.

Family inputs indicate his father, unknown McMullen, could have died in Civil War.

Hope to find more info on parents of William and Elisa (or Eliza) McMullen.

Census often spells name as Mcmullin.

Thanks