John Skey Eustace (10 August 1760 in Flushing, Province of New York, British America – 25 August 1805 in Newburgh, New York) was an officer and a veteran of both the American and French Revolutionary Wars.[1] A mercurial figure, Eustace was a revolutionary soldier, colonel of the Continental Army (1781), and maréchal de camp in the French Revolutionary Army between 1792 and 1793. In 1794 he supported the Batavian revolution and was arrested for a short time. In February 1797 he was expelled from France, suspected of spying for the British. He was arrested in Dover for his advice to the Dutch revolutionaries and subsequently expelled from England, after which he traveled to America and retired in New York. Eustace regularly published his official and private correspondence. Eustace was close to and corresponded with several of the Founding Fathers, however he was also regarded as a political adventurer of doubtful purpose and character.[2][3][4]