John Wilkins, Jr. was born on December 22, 1761 in Donegal (now East Donegal), Pennsylvania and raised in Carlisle. At age 15 the younger Wilkins enlisted for the American Revolution, and was assigned as Surgeon's Mate of the 4th Pennsylvania Regiment. As a result of this service Wilkins earned the nickname "Doctor". After the war Wilkins became a merchant and contractor in Pennsylvania and Presque Isle, Michigan, providing supplies and equipment to the United States Army in the Northwest Territory.