Ancestral Fille entry has him born about 1790 in Edgefield Co., South Carolina. He death is July 1856 at Fairmont, Sabine Co., TX.
Marriage to Elizabeth Isaacs 16 Mar 1812. Twelve children with Elizabeth Isaacs.
Marriage to Mahala L. Graham who was born 1799, she died about 1836.
For the United States 1790 Census index and images, that was taken in Edgfield, South Carolina, there was a title William Clark Junior in household of "William Clark Junior..."