Adding to the Chester Cty., Pa. and Augusta Cty., Va. confusion is "my" line of Alexanders. Archibald and 2 brothers (William and Andrew) left donegal for Chester Cty., about 1731. After about 10 yrs., they mooved to Augusta Cty., Va. The 3 brothers' children later scattered to Ky., N.C. and, possibly, elsewhere.
I'm a member of the DNAproject and a decendent of Archibald Alexander, b. 1708, Cty. Donegal, Ire., but I haven't yet crossed paths with the other Alexanders of Chester or Augusta Cty. Maddening!