(I hope that wasn't too confusing)
I show Robert McAdory (b. ~ 1774/1775; d. 1835) having lived in York County, SC during the census of 1800, 1810, 1820, and then having moved to Carroll County (adjacent to Attala Co, MS) for the 1830 census, and finally having died in Winston Co, MS (also adjacent to Attala County) in 1835 at the age of ~ 65. Robert's children (~ 10 of them) seem not to figure into this McAdory thread even though they lived in the vicinity of Attala County.
I show James McAdory II (b. ~1814, d. 1866), Robert's cousin by James I, to be a bit more complicated to figure out due mainly to his having had two wifes (Martha Francis Davis, 1829-1853; and Jane A. ????, 1828-1860). Further, between his two wives, and no doubt in order to complicate future genealogists research, multiple, identical first names were used between the two sets of children which was further complicated by his Uncle Robert's children having also been given many of the same first names.
Starting with James II's father, James I (b. ~1773, d. ~1815), I show James I's children by Mary Foote to have been John, Elizabeth, Martha, Robert, Mary, Williamson (b. ~ 1812, Alabama, d. 1863, in Attala County) and James II (b. ~ 1814, in Alabama; d. 1866, in Attala County).
Without going into the various business enterprises (and their were many of Williamson and James II, this seems to clarify in broad strokes the genealogical essentials of Thomas' two descendants who migrated to Mississippi. I have further details on both these McAdory's and sources if you need them, Alan.