Ann Bates (fl. 1778), was a loyalist American who spied for the British during the American War of Independence.
A Philadelphia schoolteacher, she was married to a man assigned to a British Army unit as an artillery repairman. Her husband joined the British troops evacuating Philadelphia and marching to New York City in 1778. Claiming to be a patriot, she managed to get through the American lines at Philadelphia and traveled to New York, where she became an agent in the spy ring run by Maj. John André. Under the cover name "Mrs. Barnes" she spied on American troops.
She carried a token (description still unknown) that would identify her as a British spy to an American officer who was spying for the British. But by the time she reached American headquarters at White Plains, N.Y., the officer had left the army.
Posing as a peddler, she listened in on conversations, checked out gun emplacements, and even walked into the headquarters of Gen.George Washington. "I had the Opportunity of going through their whole Army Remarking at the same time the strength & Situation of each Brigade, & the Number of Cannon with their Situation and Weight of Ball each Cannon was Charged with," she later wrote. She also helped other spies (never identified) get through the lines and stay at safe houses as they made their way back to British-held territory.