"As we may every moment expect the arrival of the French fleet, the correspondence with the culpers will be of very great importance." - Letter from General Washington to Dragoon Major Benjamin Tallmadge.
British forces occupied New York in August 1776, and the city would remain a British stronghold and a major naval base for the duration of the Revolutionary War. Though getting information from New York on British troop movements and other plans was critical to General George Washington, commander of the Continental Army, there was simply no reliable intelligence network that existed on the Patriot side at that time. That changed in 1778, when a young cavalry officer named Benjamin Tallmadge established a small group of trustworthy men and women from his hometown of Setauket, Long Island. Known as the Culper Spy Ring, Tallmadge’s homegrown network would become the most effective of any intelligence-gathering operation on either side during the Revolutionary War. (source)