He inherited his father's 153 acre farm in Newtown upon his death in 1759. He was admitted to Princeton University but he did not complete his studies as he got involved in local politics. Prior to his term as a representative, he served as a Justice on the Court of Common Pleas and the orphan's court in Kingston, Pennsylvania from 1780 to 1789.
Wynkoop married three times and had eight children.
Member Pa; member com. Member General Committee of Safety, 1776-1777. Member Continental Congress from Pa.
Member United States Ho.