Mary -
I have some information on Thomas Williamson that may be the one you are seeking. I have Thomas Williamson (b.9/18/1774 in Henrico County, VA) married to Elizabeth Hinds (d. 10/21/1821). They had Thomas Williamson (1/20/1785 - 12/27/1857) married to Sarah Lide Wilds (8/7/1793 - 3/2/1871) in 1811. She is buried at Lowder's Hill Cemetary Darlington District, SC. They had ten (10) children, one of whom was Mary Ann Williamson (8/8/1829 - 2/17/1889). She married Andrew Blackwood Charles (7/19/1827 - 1/15/1891 or 2/15/1891) on 1/1/1859. He is buried at Lowder's Hill Cemetary. I have no further information.
Does this help?
Rod