Chickasaw Freedmen are the former (African) Slaves of the Chickasaw Indians.
The Dawes Roll is a listing of those Indians (and their Slaves) who removed west, or were forced to move, during the 1800's, and who remained Citizens of their respective Nations. It does not apply to those who were residing outside of Indian Territory, regardless of their ethnicity.
Washington P LEE and family can be found in Tishomingo Co in 1850/1860 and then in Prentiss Co 1870/1880, listed as Free White Citizens of the US. Tishomingo was created from land ceded by the Chickasaw in 1832. Like many white settlers, it's probable that Washington and his family took advantage of the newly available land, moving to MS from SC around 1842/1844.
The Creek, Choctaw and Chickasaw never resided in South Carolina, and I believe the Cherokee may only have briefly held some land there in the 1700's.