Are either of these your trees Is this your tree on ancestry.com? I did a basic search there and found this. Does not yield much information but may be the same family. It also appears this was created with no source information other than someone else's ancestry tree so I'd take it with a grain of salt.
First one: https://www.ancestry.com/family-tree/person/tree/117084160/person/360165879804/facts
Thomas Campbell b. 1739 Argyll, Scotland, UK - d. 4 Sep 1778 Newberry, South Carolina. Married to Mary Elizabeth "Betty" ?? (b. 1740 Ireland - d. 1801 Newberry, South Carolina). They had the following children:
- Thomas (1744 - UNK)
- Mary (1767-1819)
- William (1770-1779)
- George G (1772-1869)
- Margaret (UNK-UNK)
There is also this tree: https://www.ancestry.com/family-tree/person/tree/162549942/person/322118626097/facts?_phsrc=Wkt14287&_phstart=successSource This one just shows Thomas married to Mary Elizabeth and son George. It also shows a father John Campbell (1693-1770) and mother Mary Drummond Bellenden (1685-1736). Again, no source documentation though.
Other information located through an ancestry.com search:
1. A Thomas Campbell arrived in South Carolina in 1767. Source bibliography says "ONES, JACK MORELAND, and MARY BONDURANT WARREN. South Carolina Immigrants, 1760 to 1770. Danielsville, GA: Heritage Papers, 1988. 430p.
2. A Thomas Campbell arrived in South Carolina between 1766-1767. Source bibliography says "REVILL, JANIE. A Compilation of the Original Lists of Protestant Immigrants to South Carolina, 1763-1773. Columbia [S.C.]: State Co., 1939. 163p. Reprinted by Genealogical Publishing Co., Baltimore, 1981."