At least twenty. Who lived in Pennsylvania before 1800.
After 1800? I shudder to think.
My paternity leave project this past winter was to figure out the mystery of my wife’s third-great-grandfather, William Slough. Or more accurately, that of his father, Jacob Slough. I think I figured it out, but the record was so slim, I could not feel confident of my conclusions until I had eliminated all of the other Jacob Sloughs.