There is a certain similarity to the migrations, yes, but "everyone" was going west, it seems, and my folks all show up in pretty much the same counties while migrating westward, with exceptions, of course. It would seem that they tend to be different counties and different spousal surnames, however. But also, on the however side, I find possible relations popping up rather frequentlyin the area ofWashington County, PA -- my Robert, your John, Terese Hansen's George ( http://genforum.genealogy.com/aiken/messages/875.htmlhttp://genforum.genealogy.com/aiken/messages/875.html ), John Thompson's Samuel who appears to have taken his family to Canada ( RootsWeb WorldConnect, johndnaguy, # I1536 (i1536)). All seeminly Scotch-Irish from Ulster.
My Robert was to have worked for a time (briefly) in Fredrick, MD (Gaunts Iron Works?) before "Robert Aikins, a native of Ireland and Mary Aettaburn of Wash county Pa. were married in 1787. And in 1795 moved to Ohio Belmont Co. near St Clarrsville And in 1808 moved to Morgan County Ohio" (Aikins Family Bible).
Some of the political boundaries may differ, but these folks are all in the same region at the same time, and I find it intriguing. I have not pursued any of my immigrant ancestors to their European roots (have to save something to do for the future ... ) and my ancestor Robert is another one who is not precisely pinned down.