Thomas Oldham represented Chowan County in the North Carolina Colonial Assembly from 1773 to 1775. A member of the Chowan County Committee of Safety in 1774, Oldham helped draft the county's nonimportation resolves and later represented Chowan at the first and second North Carolina Provincial Congress. Oldham's loyalties ultimately shifted and he left the state by 1779, after which point his property came under confiscation law. His petitions to reclaim his citizenship were unsuccessful and his lands for forfeited in May 1782.