You might pursue John Erskine by following his parents in the US Census. John Erskine of Monroe, Virginia, born about 1794, married Sarah Sally Young also of Monroe in 1817. They moved to Paint Twp, Highland County, Ohio, about 1826 with their oldest son, John, who was an infant. Accompanying them was another Erskine family, my ancestor Michael, with his wife Nancy Murdock Erskine and their infant son Madison. You can find the Erskines in the 1830 US Census for Paint Township, Highland County, Ohio.
I understand from other correspondents that the parents John and Sally moved to Iowa, where they died after 1870 in Marion County.
Check out many spellings for Erskine: Erskin, Erskins, Askin, Askins, Erksin -- and that's only the beginning!