Dr. Benjamin Church was the surgeon general of the Continental Army who was a spy for the British from 1772-1775, when he was caught divulging intelligence regarding American munitions, military plans, and equipment during the Revolutionary War. He was tried and convicted of treason, sentenced to life in prison. He was later exiled to the West Indies in 1780, but the ship he was being transported on was lost at sea and never found.
(From: http://www.dia.mil/News/Articles/Article-View/Article/566969/doomed-fate-of-dr-benjamin-church/)