If you are a descendant of Captain William McGill, we are definitely kinsmen. Captain William married Margaret (I believe Henderson, as that name is carried down as a middle name, including my fathers) They had three sons, William Henderson, James and Helm.When Captain William died, Margaret married a John McMillen and move the family to Mercer County.
William Henderson and James lived in Harrisville, Butler County PA, where I was born.I can trace my line back to Captain William and am in the William Henderson McGill line.If you are also in that line, and want to send me information as far back as you can, we can piece together where we branch off.
If you prefer to do by e-mail, send me the address as I also have some records that I can scan and attach.
Don't know if you are still in the area, but William Henderson and James and many of their descendants are buried in Prairie Cemetery in Harrisville PA.
Final point of interest, look up the Oak Noggin B&B in Jefferson Hills on the internet.It is made of two 18th century log cabins, one of which is Captain William McGill's