This may not be the same person, but my facts are pretty close. I have a John Nickell from County Tyrone (Gorton)Ireland (1724-1774). He emigrated to Virginia and first married a Lewis, and then Barbara McCombe. His father was John Nicholl (a. 1670-1730) also from County Tyrone. His grandfather was another John Nicholl (a. 1645-1700) from County Tyrone. And I believe his great-grandfather was William Nicholl (a.1605-1665) from Scotland. Ihaven't been able to go beyond this. I hope this is the same person.