The Secret War
Espionage was important in the war. Because of divided loyalties in the American population, both sides could draw on intelligence provided by local informants and spies. The potential significance of these undercover agents was proven at the very beginning of the conflict, with the efforts of Joseph Warren's network to warn the Patriots of the British raid on Concord. American and British leaders valued highly the information provided by clandestine agents. Shadowing the movements of armies was a secret war waged by spies and spy-hunters.Origins of a Clandestine Service
The British had long experience at running networks of agents through the military. During the war, the British took advantage of information provided by loyalists, sometimes acting alone, sometimes organized into rings. The British scored a notable intelligence coup early in the war when they were able to obtain detailed plans of Fort Washington on the Hudson from an Englishman who had served in the garrison. This information enabled the British to take advantage of Fort Washington's weaknesses when they assaulted and captured it in the fall of 1776. The British secret service also had a good deal of success infiltrating the American diplomatic corps. Two members of Benjamin Franklin's personal staff were British agents who passed on important documents.
Nathan Hale was the most famous and unfortunate American spy of the Revolutionary War. Captured behind enemy lines on Rhode Island, he was hanged on September 22, 1776. His last words were reportedly, “I only regret that I have but one life to lose for my country.”
The Americans organized a rudimentary intelligence service at the beginning of the war. Congress created a committee to collect intelligence. The committee set up an international network of contacts to collect information and sometimes searched the mails for valuable bits of intelligence. The useful information gleaned from these and other sources was passed on to American military and political leaders. In addition to acting as an intelligence agency, the committee engaged in covert operations, buying and smuggling arms and munitions. Benjamin Franklin and his fellow diplomats in Europe were heavily involved in this clandestine trade.
Congress organized a counterintelligence service. The Commission for Detecting and Defeating Conspiracies operated within strict rules laid down in the Articles of War published in 1776. These definitions of treason and espionage were used in judicial proceedings against suspected spies. The Commission used agents and the support of militia to detect and apprehend British agents.George Washington, Spymaster
George Washington was a devoted and skillful practitioner of the secret war. He spent huge sums for intelligence. He sometimes handled spies himself and acted as his own intelligence analyst. He even used agents to assist in efforts at strategic deception, most notably in 1781, when he tried to persuade General Clinton that he was preparing an attack on New York City to divert attention from the real objective — Cornwallis's army at Yorktown.
Washington made use of a spy named William Honeyman to gather intelligence about Trenton. Honeyman, a former British soldier, wandered through the town, making notes on its defenses. Then he entered American lines, pretending to be a drover, and took his information directly to the Commander in Chief. Washington established networks of spies in British-occupied Philadelphia and New York. In Philadelphia, a ring of agents headed by Major John Clark smuggled valuable information to Washington while he was at Valley Forge. Major Benjamin Tallmadge organized a spy network in New York and Long Island. Robert Townshend, a merchant; Hercules Mulligan, a tailor; and Samuel Culper, a farmer, were among the members of the “Culper Ring” that provided intelligence on British plans and operations. The Culper Ring learned that there was a British agent close to Washington and transmitted information that helped foil Benedict Arnold's treachery.