The 1850, 1860, and 1870 U.S. census records in Jones, Mississippi list Thomas C. and Lydia Bryant. The 1850 census includes a 7-year old daughter, Virginia, born in Mississippi, so unless Lydia was a second wife they were married before 1847. Thomas homesteaded two parcels of land, in Jones County, 40 acres in 1860 and 120 more in 1861. Everyone is listed on the census as white. If Lydia was Native American she would have been Choctaw since the Cherokee never lived in Mississippi. There are pre-Removal Choctaw census records, but you’d need to know her family name. The ‘Tom Mccauley’ story sounds pretty sketchy. The outlaw Tom apparently went to California in the Gold Rush, but where he came from is unknown.