All I have is what I already posted. I can tell you that the Mackey's (back then in 1800 or so) were associated with the Duke and McGarrah; AKA the McGarragh/McGarry/McGurragh/Magara family in Lancaster, SC. Mackey was sometimes seen as McKee, and McKay. I think that these latter 2 families may have come from Ireland together, and before that, Scotland. There are also records of the Mackeys being in Lunenburg Co., VA, before they went to SC, so maybe that info will help (?) I would try the latest SC U.S. Federal census, (on Ancestry.com) then work backwards from there. That's the best I can do for you; hope it helps.