There was no United States when Washingtons parents and grandparents were born.
George Washington and the first few president were covered by the “grandfather clause” in the presidential eligibility clause of our U.S. Constitution: https://www.scribd.com/doc/48856102/All-U-S-Presidents-Eligibility-Grandfather-Clause-Natural-Born-Citizen-Clause-or-Seated-by-Fraud