William was the 3rd and last child born of Jefferson Bartholomew (1808-1848) and his 1st wife Sarah (Sallie) Bartholomew (1811-1840).
William married Mary L. Parks (Merriam) (1841-1921) by whom he had at least two children: Henry (b. 1870) & Sarah (b. 1874). Mary brought into her marriage with William two daughters: Edna (b. 1862) & Cora (b. 1864).