Episode 025

Spying During the Revolutionary War – Part II

We continue with Part II of our discussion on spying during the Revolutionary War, with conversations around the "Turtle", Washington's big communication break, and stories of several of his intelligence agents.

This week we’ll continue our discussion on spying during the Revolutionary War, starting with the fact that the Continental Congress regularly received quantities of intercepted British and Loyalist mail. On November 20, 1775, it received some intercepted letters from Cork, Ireland, and appointed a committee made up of John Adams, Benjamin Franklin, Thomas Johnson, Robert Livingston, Edward Rutledge, James Wilson and George Wythe “to select such parts of them as ma y be proper to publish.” The Congress later ordered a thousand copies of the portions selected by the Committee to be printed and distributed. A month later, when another batch of intercepted mail was received, a second committee was appointed to examine it. Based on its report, the Congress resolved that “the contents of the intercepted letters this day read, and the steps which Congress may take in consequence of said intelligence thereby given, be kept secret until further orders.” By early 1776, abuses were noted in the practice, and Congress resolved that only the councils or committees of safety of each colony, and their designees, could henceforth open the mail or detain any letters from the post.

When Moses Harris reported that the British had recruited him as a courier for their Secret Service, General Washington proposed that General Schuyler “contrive a means of opening them without breaking the seals, take copies of the contents, and then let them go on. By these means we should become masters of the whole plot.” From that point on, Washington was privy to British intelligence pouches between New York and Canada.


Dr. James Jay used the advanced technology of his time in creating the invaluable “sympathetic stain” used for secret communications. Perhaps the American Patriots’ most advanced application of technology was in David Bushnell’s Turtle, a one-man submarine created for affixing watchwork-timed explosive charges to the bottom of enemy ships.

The “turtle,” now credited with being the first use of the submarine in warfare, was an oaken chamber about five-and-a-half feet (1.6 m) wide and seven feet (2.1 m) high. It was propelled by a front-mounted, pedal-powered propeller at a speed of up to three miles per hour (5 km/h), had a barometer to read depth, a pump to raise or lower the submarine through the water, and provision for both lead and water ballast.

When Bushnell learned that the candle used to illuminate instruments inside the “turtle” consumed the oxygen in its air supply, he turned to Benjamin Franklin for help. The solution: the phosphorescent weed, foxfire. Heavy tides thwarted the first sabotage operation. A copper-clad hull which could not be penetrated by the submarine’s auger foiled the second. (The “turtle” did blow up a nearby schooner, however.) The secret weapon would almost certainly have achieved success against a warship if it had not gone to the bottom of the Hudson River when the mother ship to which it was moored was sunk by the British in October 1776.

An early device developed for concealing intelligence reports when traveling by water was a simple weighted bottle that could be dropped overboard if there was a threat of capture. This was replaced by a wafer-thin leaden container in which a message was sealed. It would sink in water, and melt in fire, and could be used by agents on land or water. It had one drawback—lead poisoning if it was swallowed. It was replaced by a silver, bullet-shaped container that could be unscrewed to hold a message and which would not poison a courier who might be forced to swallow it.

Intelligence analysis and estimates

On May 29, 1775, the Continental Congress received the first of many intelligence estimates prepared in response to questions it posed to military commanders. The report estimated the size of the enemy force to be encountered in an attack on New York, the number of Continental troops needed to meet it, and the kind of force needed to defend the other New England colonies.

An example of George Washington’s interest in intelligence analysis and estimates can be found in instructions he wrote to General Putnam in August 1777:

“Deserters and people of that class always speak of number. . . indeed, scarce any person can form a judgement unless he sees the troops paraded and can count the divisions. But, if you can by any means obtain a list of the regiments left upon the island, we can compute the number of men within a few hundreds, over or under.” On another occasion, in thanking James Lovell for a piece of intelligence, Washington wrote: “it is by comparing a variety of information, we are frequently enabled to investigate facts, which were so intricate or hidden, that no single clue could have led to the knowledge of them. . . intelligence becomes interesting which but from its connection and collateral circumstances, would not be important.”

Colonel David Henley, Washington’s intelligence chief for a short period in 1778, received these instructions when he wrote to Washington for guidance: “Besides communicating your information as it arises. . . you might make out a table or something in the way of columns, under which you might range, their magazines of forage, grain and the like, the different corps and regiments, the Works, where thrown up, their connexion, kind and extent, the officers commanding, with the numbers of guns &ca. &ca. This table should comprehend in one view all that can be learned from deserters, spies and persons who may come out from the enemy’s boundaries.” (It was common practice to interrogate travelers from such British strongholds as New York, Boston and Philadelphia.)


George Washington

George Washington was a skilled manager of intelligence. He utilized agents behind enemy lines, recruited both Tory and Patriot sources, interrogated travelers for intelligence information, and launched scores of agents on both intelligence and counterintelligence missions. He was adept at deception operations and tradecraft and was a skilled propagandist. He also practiced sound operational security.

As an intelligence manager, Washington insisted that the terms of an agent’s employment and his instructions be precise and in writing. He emphasized his desire for receiving written, rather than verbal, reports. He demanded repeatedly that intelligence reports be expedited, reminding his officers of those bits of intelligence he had received which had become valueless because of delay in getting them to him. He also recognized the need for developing many different sources so that their reports could be cross-checked, and so that the compromise of one source would not cut off the flow of intelligence from an important area.

Washington sought and obtained a “secret service fund” from the Continental Congress, and expressed preference for specie, preferably gold: “I have always found a difficulty in procuring intelligence by means of paper money, and I perceive it increases.” In accounting for the sums in his journals, he did not identify the recipients: “The names of persons who are employed within the Enemy’s lines or who may fall within their power cannot be inserted.”

He instructed his generals to “leave no stone unturned, nor do not stick to expense” in gathering intelligence, and urged that those employed for intelligence purposes be those “upon whose firmness and fidelity we may safely rely.”

Washington’s intelligence officers

Washington retained full and final authority over Continental Army intelligence activities, but he delegated significant field responsibility to trusted officers. Although he regularly urged all his officers to be more active in collecting intelligence, Washington relied chiefly on his aides and specially designated officers to assist him in conducting intelligence operations. The first to assume this role appears to have been Joseph Reed, who fulfilled the duties of “Secretary, Adjutant General and Quarter Master, besides doing a thousand other little Things which fell incidentally.” A later successor to Reed was Alexander Hamilton, who is known to have been deeply involved with the Commander-in-Chief’s intelligence operations, including developing reports received in secret writing and investigating a suspected double agent.

When Elias Boudinot was appointed Commissary General of Prisoners, responsible for screening captured soldiers and for dealing with the British concerning American patriots whom they held prisoner, Washington recognized that the post offered “better opportunities than most other officers in the army, to obtain knowledge of the Enemy’s Situation, motions and… designs,” and added to Boudinot’s responsibilities “the procuring of intelligence.” In 1778, Washington selected Brigadier General Charles Scott of Virginia as his “intelligence chief.” When personal considerations made it necessary for Scott to step down, Washington appointed Colonel David Henley to the post temporarily, and then assigned it to Major Benjamin Tallmadge. Tallmadge combined reconnaissance with clandestine visits into British territory to recruit agents, and he attained distinction for his conduct of the Culper Ring operating out of New York.

In 1776, George Washington picked Thomas Knowlton to command the Continental Army’s first intelligence unit, known as “Knowlton’s Rangers.” Intelligence failure during the battle of Long Island convinced Washington that he needed an elite detachment dedicated to reconnaissance that reported directly to him. Knowlton, who had served in a similar unit during the French and Indian War, led 130 men and 20 officers—all hand-picked volunteers—on a variety of secret missions that were too dangerous for regular troops to conduct. The date 1776 on the seal of the Army’s intelligence service today refers to the formation of Knowlton’s Rangers.

Other intelligence officers who served with distinction during the War of Independence included Captain Eli Leavenworth, Major Alexander Clough, Colonel Elias Dayton, Major John Clark, Major Allan McLane, Captain Charles Craig and General Thomas Mifflin.

Paul Revere and the Mechanics

Dr. Joseph Warren

The first Patriot intelligence network on record was a secret group in Boston known as the Mechanics, which meant skilled workers. The group, also known as the Liberty Boys, apparently grew out of the old Sons of Liberty organization that had successfully opposed the Stamp Act. The Mechanics organized resistance to British authority and gathered intelligence. In the words of one of its members, Paul Revere, “in the Fall of 1774 and winter of 1775, I was one of upwards of thirty, chiefly mechanics, who formed ourselves into a Committee for the purpose of watching British soldiers and gaining every intelligence on the movements of the Tories.” According to Revere, “We frequently took turns, two and two, to watch the (British) soldiers by patrolling the streets all night.”

In addition, the Mechanics sabotaged and stole British military equipment in Boston. Their security practices, however, were amateurish. They met in the same place regularly (the Green Dragon Tavern), and one of their leaders (Dr. Benjamin Church) was a British agent.

Through their intelligence sources, the Mechanics were able to see through the cover story the British had devised to mask their march on Lexington and Concord. Dr. Joseph Warren, chairman of the Committee of Safety, charged Revere with the task of warning Samuel Adams and John Hancock at Lexington, Massachusetts, that they were the probable targets of the enemy operation. Revere arranged for the warning lanterns to be hung in Old North Church to alert patriot forces at Charlestown, and then set off on his famous ride. He completed his primary mission of notifying Adams and Hancock. Then Revere, along with Dr. Samuel Prescott and William Dawes, rode on to alert Concord, only to be apprehended by the British en route. Dawes got away, and Dr. Prescott managed to escape soon afterward and to alert the Patriots at Concord. Revere was interrogated and subsequently released, after which he returned to Lexington to warn Hancock and Adams of the proximity of British forces.

Revere then turned to another mission, retrieving from the local tavern a trunk belonging to Hancock and filled with incriminating papers. With John Lowell, Revere went to the tavern and, as he put it, during “a continual roar of Musquetry… we made off with the Trunk.”

Paul Revere had served as a courier prior to his “midnight ride” and continued to do so during the early years of the war. One of his earlier missions was perhaps as important as the Lexington ride. In December 1774, Revere rode to the Oyster River in New Hampshire with a report that the British, under General Thomas Gage, intended to seize Fort William and Mary. Armed with this intelligence, Major John Sullivan of the colonial militia led a force of four hundred men in an attack on the fort. The one hundred barrels of gunpowder taken in the raid were ultimately used by the Patriots to cover their retreat from Bunker Hill.


Nathan Hale

Nathan Hale is probably the best known but least successful American agent in the War of Independence. He embarked on his espionage mission into British-held New York as a volunteer, impelled by a strong sense of patriotism and duty. Before leaving on the mission he reportedly told a fellow officer: “I am not influenced by the expectation of promotion or pecuniary award; I wish to be useful, and every kind of service necessary to the public good becomes honorable by being necessary. If the exigencies of my country demand a peculiar service, its claims to perform that service are imperious.”

But dedication was not enough. Captain Hale had no training experience, no contacts in New York, no channels of communication, and no cover story to explain his absence from camp—only his Yale diploma supported his contention that he was a “Dutch schoolmaster.” He was captured while trying to slip out of New York, was convicted as a spy and went to the gallows on September 22, 1776. Witnesses to the execution reported the dying words that gained him immortality (a paraphrase of a line from Joseph Addison’s play Cato): “I only regret that I have but one life to lose for my country.” After he was accused of being a spy he stated his name, rank, and his reason for being there. He gave a soldier a letter to his family, which he ripped up. He asked to see a bible and was denied the right.

Haym Salomon

The same day that Nathan Hale was executed in New York, British authorities arrested another Patriot and charged him with being a spy. Haym Salomon was a recent Jewish immigrant who worked as a stay-behind agent after Washington evacuated New York City in September 1776. Salomon was arrested in a round-up of suspected Patriot sympathizers and was confined to Sugar House Prison. He spoke several European languages and was soon released to the custody of General von Heister, commander of Hessian mercenaries, who needed someone who could serve as a German language interpreter in the Hessian commissary department. While in German custody, Salomon induced a number of the German troops to resign or desert.

Eventually paroled, Salomon did not flee to Philadelphia as had many of his New York business associates. He continued to serve as an undercover agent and used his personal finances to assist American patriots held prisoner in New York. He was arrested again in August 1778, accused this time of being an accomplice in a plot to burn the British fleet and to destroy His Majesty’s warehouses in the city. Salomon was condemned to death for sabotage, but he bribed his guard while awaiting execution and escaped to Philadelphia. There he came into the open in the role for which he is best known, as an important financier of the Revolution.

Abraham Patten

Less than a year after Nathan Hale was executed, another American agent went to the gallows in New York. On June 13, 1777, General Washington wrote the President of Congress: “You will observe by the New York paper, the execution of Abm. (Abraham) Patten. His family deserves the generous Notice of Congress. He conducted himself with great fidelity to our Cause rendering Services and has fallen a Sacrifice in promoting her interest. Perhaps a public act of generosity, consideri ng the character he was in, might not be so eligible as a private donation.”

Culper Ring

“Most accurate and explicit intelligence” resulted from the work of Abraham Woodhull on Long Island and Robert Townsend in British-occupied New York City. Their operation, known as the Culper Ring from the operational names used by Woodhull (Culper, Sr.) and Townsend (Culper, Jr.), effectively used such intelligence tradecraft as codes, ciphers and secret ink for communications; a series of couriers and whaleboats to transmit reporting; at least one secret safe house, and numerous sources. The network was particularly effective in picking up valuable information from careless conversation wherever the British and their sympathizers gathered.

One female member of the Culper Ring, known only by her codename “355,” was arrested shortly after Benedict Arnold’s defection in 1780 and evidently died in captivity. Details of her background are unknown, but 355 (the number meant “lady” in the Culper code) may have come from a prominent Tory family with access to British commanders and probably reported on their activities and personalities. She was one of several females around the debonaire Major André, who enjoyed the company of young, attractive, and intelligent women. Abraham Woodhull, 355’s recruiter, praised her espionage work, saying that she was “one who hath been ever serviceable to this correspondence.” Arnold questioned all of André’s associates after his execution in October 1780 and grew suspicious when the pregnant 355 refused to identify her paramour. She was incarcerated on the squalid prison ship Jersey, moored in the East River. There she gave birth to a son and then died without disclosing that she had a common-law husband–Robert Townsend, after whom the child was named.

One controversial American agent in New York was the King’s Printer, James Rivington. His coffee house, a favorite gathering place for the British, was a principal source of information for Culper, Jr. (Townsend), who was a silent partner in the endeavor. George Washington Parke Custis suggests that Rivington’s motive for aiding the patriot cause was purely monetary. Custis notes that Rivington, nevertheless, “proved faithful to his bargain, and often would provide intelligence of great importance gleaned in convivial moments at Sir William’s or Sir Henry’s table, be in the American camp before the convivialists had slept off the effects of their wine. The King’s printer would probably have been the last man suspected, for during the whole of his connection with the secret service his Royal Gazette piled abuse of every sort upon the cause of the American general and the cause of America.” Rivington’s greatest espionage achievement was acquiring the Royal Navy’s signal book in 1781. That intelligence helped the French fleet repel a British flotilla trying to relieve General Cornwallis at Yorktown.

Hercules Mulligan

Hercules Mulligan was a textile importer and ran a clothing shop that was also frequented by British officers in occupied New York. The Irish immigrant was a genial host, and animated conversation typified a visit to his emporium. Mulligan was the first to alert Washington to two British plans to capture the American Commander-in-Chief and to a planned incursion into Pennsylvania. Besides being an American agent, Mulligan also was a British counterintelligence failure. Before he went underground as an agent, he had been an active member of the Sons of Liberty and the New York Committees of Correspondence and Observation, local Patriot intelligence groups. Mulligan had participated in acts of rebellion, and his name had appeared on Patriot broadsides distributed in New York as late as 1776. But every time he fell under suspicion, the popular Irishman used his gift of “blarney” to talk his way out of it. The British evidently never learned that Alexander Hamilton, Washington’s aide-de-camp, had lived in the Mulligan home while attending King’s College, and had recruited Mulligan and possibly Mulligan’s brother, a banker and merchant who handled British accounts, for espionage. Mulligan was assisted by his slave, Cato, who performed dangerous assignments as a courier.

Lewis Costigin

Lieutenant Lewis J. Costigin, walked the streets of New York freely in his Continental Army uniform as he collected intelligence. Costigin had originally been sent to New York as a prisoner and was eventually paroled under oath not to attempt escape or communicate intelligence. In September 1778, he was designated for prisoner exchange and freed of his parole oath. But he did not leave New York, and until January 1779 he roamed the city in his American uniform, gathering intelligence on British commanders, troop deployments, shipping, and logistics while giving the impression of still being a paroled prisoner.

William Heath

On May 15, 1780, General Washington instructed General Heath to send intelligence agents into Canada. He asked that they be those “upon whose firmness and fidelity we may safely rely,” and that they collect “exact” information about Halifax in support of a French requirement for information on the British defense works there. Washington suggested that qualified draftsmen be sent. James Bowdoin, who later became the first president of the American Academy of Arts and Science, fulfilled the intelligence mission, providing detailed plans of Halifax harbor, including specific military works and even water depths.

Daniel Bissell

In August 1782, General Washington created the Badge of Military Merit, to be issued “whenever any singularly meritorious action is performed… not only instances of unusual gallantry, but also of extraordinary fidelity and essential service in any way.” Through the award, said Washington, “the road to glory in a Patriot army and a free country is thus open to all.” The following June, the honor was bestowed on Sergeant Daniel Bissell, who had “deserted” from the Continental Army, infiltrated New York, posed as a Tory, and joined Benedict Arnold’s “American Legion.” For over a year, Bissell gathered information on British fortifications, making a detailed study of British methods of operation, before escaping to American lines.

Dominique L’Eclise

Dominique L’Eclise, a Canadian who served as an intelligence agent for General Schuyler, had been detected and imprisoned and had all his property confiscated. After being informed by General Washington of the agent’s plight, the Continental Congress on October 23, 1778, granted $600 to pay L’Eclise’s debts and $60, plus one ration a day “during the pleasure of Congress,” as compensation for his contribution to the American cause.

Lydia Darragh

Family legend contributes the colorful but uncorroborated story of Lydia Darragh and her listening post for eavesdropping on the British. Officers of the British force occupying Philadelphia chose to use a large upstairs room in the Darragh house for conferences. When they did, Mrs. Darragh would slip into an adjoining closet and take notes on the enemy’s military plans. Her husband, William, would transcribe the intelligence in a form of shorthand on tiny slips of paper that Lydia would then position on a button mold before covering it with fabric. The message-bearing buttons were then sewn onto the coat of her fourteen-year-old son, John, who would then be sent to visit his elder brother, Lieutenant Charles Darragh, of the American forces outside the city. Charles would snip off the buttons and transcribe the shorthand notes into readable form for presentation to his officers.

Lydia Darragh is said to have concealed other intelligence in a sewing-needle packet which she carried in her purse when she passed through British lines. Some espionage historians have questioned the credibility of the best-known story of Darragh’s espionage: that she supposedly overheard British commanders planning a surprise night attack against Washington’s army at Whitemarsh on December 4, 1777. The cover story she purportedly used to leave Philadelphia—she was filling a flour sack at a nearby mill outside the British lines because there was a flour shortage in the city—is implausible because there was no shortage and a lone woman would not have been allowed to roam around at night, least of all in the area between the armies.

Also published on Medium.

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