Maggie the interesting thing is that my grandfather Alexander McQuillan, whom I'm named after, was also born in northern Ireland in Ballymena Co. Antrim in 1912. He remained all his life there when he died in 1962. Not sure of the relationship (if any) but there seems to be several lines of McQuillans. The one I belong to have always been cattle dealers but interestingly enough I went school with McQuillans from Belfast who were involved in the construction industry. My Clan all came from the 'Glens of Antrim' where they've along history there. Good luck with your search.