Philadelphia merchant and philanthropist.

Delaware militia officer and assemblyman (1759, 1761). Moved to Philadelphia (c. 1762). Member of the American Philosophical Society (1768). Contributed to the College of Philadelphia, the Pennsylvania Hospital, the Philadelphia silk filature, and other civic institutions. Enthusiastic supporter of James Rumsey; treasurer of the Rumseian Society. Retired from business (c. 1793) and devoted himself to perfecting a machine for pumping and ventilating ships.

Son of Abraham and Esther (Fisher) Wynkoop of Sussex County, Delaware. Married Sarah Woodrop Sims (1767); eight children. Name usually spelled “Wynkoop.”

First letter in correspondence: May 1, 1788;Whitfield J. Bell, Jr., Patriot-Improvers: Biographical Sketches of Members of the American Philosophical Society (2 vols., Philadelphia, 1999), ii, 336-9.