The Culper Spy Ring was an American spy network operating during the War of American Independence that provided George Washington with information on British troop movements. In November 1778, George Washington appointed Major Benjamin Tallmadge as director of military intelligence, charged with creating a spy ring in New York City, the site of British headquarters.
Benjamin Tallmadge oversaw the Culper Spy Ring operating out of New York (litchfieldhistoricalsociety.org)
This network became known as the Culper Spy Ring and operated successfully in and around New York City for five years, during which time no spy was ever unmasked. Indeed even Washington was ignorant of the spies' identities. Tallmadge's informants consisted of friends he made at school on Long Island, including Austin Roe, Caleb Brewster, Abraham Woodhull, and Anna Strong.
Though Woodhull was Tallmadge's chief agent, Robert Townsend was an important informant who posed as a Loyalist coffee-shop owner and merchant while working as a society journalist. As a reporter Townsend was able to obtain information from the British at society gatherings.
In order to safeguard the identity of his spies, Tallmadge utilized a number of protective measures. Tallmadge gave his informants pseudonyms and invented a numerical substitution system to identify his informants rather than use names. Seven hundred and sixty-three numbers were used, with 711 denoting General Washington, 745 representing England and 727 for New York. Tallmadge and his associates also wrote in invisible ink.
The spy ring established a sophisticated method of conveying information to Washington, who was based at New Windsor in New York. As a result, all information sent to Washington had to be transported through British-held territory. Austin Roe rode from Setauket, Long Island, to New York City, where he entered Townsend's establishment. There Roe placed an order from Tallmadge who signed under his code name John Bolton.
Contained in this message were prearranged code words from Washington to Tallmadge to which Tallmadge responded in code. The messages were then hidden in goods that Roe took back to Setauket, and hid on a farm belonging to Abraham Woodhull who would later retrieve the messages. Anna Strong, who owned a farm near to Woodhull's barn, would then hang a black petticoat on her clothesline that Caleb Brewster could see in order to signal him to retrieve the documents. Strong indicated which cove Brewster should land at by hanging up handkerchiefs to designate the specific cove. Brewster would then deliver the messages to Tallmadge.
The spy ring played an important role in the Revolutionary War. For instance, in 1780 the group learned that the British under the command of General Henry Clinton were about to launch an expedition in Rhode Island. Tallmadge contacted Washington who immediately ordered his army into an offensive position causing Clinton to cancel the attack. The group was also responsible for the apprehension of the British spy Major John André.
Victoria Williams, Ph.D.
Crowdy, Terry. The Enemy Within: A History of Espionage. Oxford: Osprey Publishing, 2006.
Nagy, John A. Invisible Ink: Spycraft of the American Revolution. Yardley, PA: Westholme Publishing, 2009.
Rose, Alexander. Washington's Spies: The Story of America's First Spy Ring. New York: Bantam Books, 2007.
Spy Letters of the American Revolution (Clements Library, University of Michigan)