My Mercer County families are MCMILLEN & ROBB. Specifically, James Robb who married Martha and filed a will in Mercer Co in 1803 although I believe he died in Westmoreland Co. His daughter Elizabeth married Daniel McMillen. I have a double descendency from this couple through their daughter Ann who married Michael Geyer in 1820 and their son Jonathan who married Eliza Barclay. Would love to share information. Robbie Dyer