How to be a Revolutionary War Spy Master

Espionage and Cryptography

April 12, 2018
by Don N. Hagist Also by this Author


Journal of the American Revolution is the leading source of knowledge about the American Revolution and Founding Era. We feature smart, groundbreaking research and well-written narratives from expert writers. Our work has been featured by the New York Times, TIME magazine, History Channel, Discovery Channel, Smithsonian, Mental Floss, NPR, and more. Journal of the American Revolution also produces annual hardcover volumes, a branded book series, and the podcast, Dispatches

George Washington is credited with being a great spy master, and the feats of his Culper spy ring have become famous. How did he learn this clandestine craft? Although he had military experience, prior to 1775 he hadn’t served in the headquarters and staff positions that were usually the hub of intelligence gathering activities. But Washington had other experienced men around him, and he also had the resource through which officers in all of the era’s armies learned much of their trade: books.

Many military textbooks were available in the English language during the eighteenth century, many readily available from printers and booksellers in America. Anyone who could read could easily learn the theory of marching maneuvers, tactics, fortification, and other aspects of the military arts. There was no one book devoted solely to intelligence gathering, but some texts included sections and chapters on the subject, providing common-sense general instructions on the employment of spies. With a few good books, every officer of rank on both sides of the conflict had the rudiments of spycraft at his fingertips.

An example is in a popular mid-century work, Military Instructions by the King of Prussia. Written by the great military thinker Frederick II of Prussia and published in German in 1748, an English-language edition appeared in London in 1762.[1]The twelfth chapter, or article, is called, “Of Spies, how they are to be employed on every Occasion, and in what Manner we are to learn Intelligence of the Enemy.” It begins with the observation, “If we were acquainted beforehand with the intentions of the enemy, we should always be more than a match for him even with an inferior force. It is an advantage which all generals are anxious to procure, but very few obtain.” The chapter continues,

Spies may be divided into several classes: 1st, common people who choose to be employed in such concern; 2dly, double spies; 3dly, spies of consequence; 4thly, those who are compelledto take up the unpleasant business.
   The common gentry, viz. peasants, mechanics, priests, &c. which are sent into the camp, can only be employed to discover wherethe enemy is: and their reports are generally so incongruous and obscure, as rather to increase our uncertainties than lessen them.
   The intelligence of deserters is, for the most part, not much more to be depended on. A soldier knows very well what is going forward in his own regiment, but nothing farther. The hussars being detached in front, and absent the greatest part of their time from the army, are often ignorant on which side it is encamped. Nevertheless, their reports must be committed to paper, as the only means of turning them to any advantage.
   Double spies are used to convey false intelligence to the enemy.

The author gives examples from European campaigns – of providing a known spy with false information to lure an opponent into a trap; of a postmaster paid to open and copy letters; of a king’s secretary who was discovered to be a spy, and was then regularly provided with deceptive information. During the American Revolution, James Armisteadwas among the “common people” who successfully infiltrated an enemy camp and became a “spy of consequence.”

In spite of having doubted the value of information from deserters, Frederick II recommended using soldiers posing as deserters to send bogus information:

When we wish to gain intelligence of the enemy, or give him a false impression of our situation and circumstances, we employ a trusty soldier to go from our camp to that of the enemy, and report what we wish to have believed. He may also be made the bearer of hand-bills calculated to encourage desertion. Having completed his business, he may take a circuitous march and return to camp.

This is akin to the activities of American spy Daniel Bissell, who went so far as to enlist in a Loyalist regiment. Frederick II also suggested a similar technique, forcing a prominent citizen to go to the enemy headquarters on some pretense or another, with a spy posing as a servant in tow. Effecting this requires coercion by holding the family or property of the citizen as hostages, which the author admitted to be “a harsh and cruel practice.” Captain Allen McLaneused an approach like this when he posed as the simple-minded son of a civilian visitor to gain intelligence about the British post at Stony Point.

Frederick’s final advice about spies is particularly important:

I must farther add, that in the payment of spies, we ought to be generous, even to a degree of extravagance. That man certainly deserves to be well rewarded, who risks his neck to do you service,

Maurice Counte de Saxe was another highly regarded military mind; his Reveries, or Memoirs concerning the Art of Warappeared in English in 1759.[2] Saxe’s chapter 10, “Of Spies and Guides,” was more succinct than Frederick II’s, but offered much of the same guidance:

One cannot bestow too much attention in the procuring of spies and guides. M. de Montecuculli says, that they serve as eyes to the head, and that they are equally as essential to a commander. Which observation of his is certainly very just. Money therefore should never be wanting, upon a proper occasion; for the acquisition of such as are good, is cheap at any price. They are to be taken out of the country in which the war is carried on, selecting those only who are active and intelligent, and dispersing them every where; amongst the general officers of the enemy, amongst his sutlers, and, above all, amongst the purveyors of provisions; because their stores, magazines, and other preparations, furnish the best intelligence concerning his real design.
   The spies are not to know one another; and are to consist of various ranks or orders; some to associate with the soldiers; others to follow the army, under the disguise of pedlars: but it is necessary that all of them should be admitted to the knowledge of some one belonging to the first order of their fraternity; from whom they may occasionally receive any thing that is to be conveyed to the general who pays them. This charge must be committed to one who is both faithful and ingenious; obliging him to render an account of himself every day, and guarding, as much as possible, against his being corrupted.

One of the recommended guises, that of a peddler, was used by the British spy Ann Bates, while the American Lt. Lewis Costigin managed to send intelligence information while a prisoner of war in New York City.

Saxe concluded his remarks with this wise observation:

I shall not insist any longer upon this subject; which, upon the whole, is a detail that depends upon a great variety of circumstances, from which a general, by his prudence and intrigues, will be able to reap great advantages.

Washington is not known to have owned a copy of Saxe’s Reveries,[3]but he did own a book by Thomas Simes, one of the most prolific British military authors of the era, in which Saxe’s section on spies was reprinted verbatim.[4]

Another book in Washington’s library, one which he recommended to his subordinates, was Essay on the Art of War, a 1761 English translation of a 1754 French volume. The section entitled “Of the General of an Army”[5]includes this succinct advice about spies:

A General should spare no Trouble or Expence to be well informed of every Thing that passes with the Enemy, either by Means of Parties, or of Spies whom he should pay well, if he would be well served: Nothing is more absolutely necessary or more useful than Spies, who Strada, with Reason, calls the Eyes and Ears of princes: We see in Scripture, that God himself commanded Moses to send out Spies to the Land of Promise, and all the Instructions a General can possibly give to the Spies he employs, are to be found in the thirteenth Chapter of Numbers.

The last sentence is worthy of a message from a spy, giving not direct guidance but a reference to another source for the information. Numbers 13 reads (approximately, depending on which translation is used),

Go up through the Negev and on into the hill country. See what the land is like and whether the people who live there are strong or weak, few or many. What kind of land do they live in? Is it good or bad? What kind of towns do they live in? Are they unwalled or fortified? How is the soil? Is it fertile or poor? Are there trees in it or not? Do your best to bring back some of the fruit of the land.

In other words, instruct your spies to gather whatever information might be useful. That’s obvious, but it’s not enough guidance to develop an intelligence program.

Essay on the Art of War goes on, however, to present much more detailed information about how spies should operate, and how they should be managed; here we see many of the methods used in some way or another by Washington throughout the war:[6]

As to Spies,those you employ should be Persons of Capacity, able to know the Strength of a Fortification or Intrenchment, either from its natural Situation or from Art; what Extent of Ground a certain Number of Infantry or Cavalry occupy commonly either in Camp or on March, according to the different Fronts in which they march, and at one Glance of their Eye be able to comprehend nearly the Strength of a Camp or Post where the Enemy are lodged; and how many Cavalry or Infantry they have in their Camp or on their March,, without being obliged to count the Tents or the Regiments. The Subjects of a neutral Prince are those who run the least Risk in serving as Spies; for under Pretence of Travelling or Traffic they can pass unsuspected from one Country to the other.
   You may also have some Officer in the Enemy’s Camp, or other Person of Ability in the Neighbourhood, who informs you of what you want to know. As often as you write to him, you can use the Cypher and Composition mentioned, letting nothing appear but a few Lines on any indifferent Subject, and subscribing the Letter with the Name of a Relation, Countryman, or Friend, of the person intrusted; so that if it is intercepted nothing appears, but one Friend writing to another on indifferent subjects, or Family Affairs.
   You will have warned the person intrusted, that if the Enemy send out a small Detachment, or try an Expedition of little Importance, he need not advise you of it; that you may not expose your Spies for Trifles. You may also have Spies among the Enemy, by making ten or twelve of your own Soldiers desert, chusing those in whom you can trust, and who possess something in their Country, or leave their Wives or Children as Pledges of their Fidelity: Name to each the particular Regiment in which he shall inlist, and let him know, that whenever a Person shall give him a Watch-word agreed on, he shall directly bring to you the Letter or any Intelligence that Person shall give him. These Soldiers should not know each other, and ought each to have a different Watch-word; so that if one is taken or proves unfaithful, the rest may not be in Danger. Neither should you name the Person of the Enemy’s Army with whom you are in Intelligence, nor give him any Mark to know him by. It is sufficient they have Orders to return when their Watch-word is given them. After having taken these Precautions, you write to the Person intrusted, that in such a Regiment there is such a Man whom you have sent there, whom he may know by such a Mark, Name, or watch-words and describing in the same Manner the rest who have deserted for that Purpose. If your Correspondent has only a Letter to send you, it is not necessary he discover himself by giving it with his own Hand: But having exactly observed the Marks by which the Soldier is to be known, he can send him the Watch-word and Letter by another trusty Person: Or if the case admits of it without Inconvenience, he can wait till Night, and when it is dark, in Disguise, passing by the Soldier, give the Watch-word and Letter. We only mention this Sort of Spies not to omit any thing; though it appears to be extremely difficult to have certain Intelligence by Means so complicated.
   It is of great Importance to gain some of those employed in the Enemy’s Secretary of State’s Office, in that of the Secretary at War, or of the General in Chief, who give you Intelligence of the Resolutions taken. There are different Ways to succeed in this, needless here to mention. A Golden Key opens every Lock.
   In general you must endeavour to draw Intelligence and Instructions from the Spies by every possible Means, but never open yourself to them. You should employ several for the fame Subject, who are absolutely ignorant of each other, never see them but in private, make them talk on different subjects; let them speak a great deal, but say you little, in order to discover their Character, and what they are fit to be employed in; then set other Spies on them, to discover if they are not employed on both Sides.
   If you would execute an Enterprize, after believing from the concurrent Reports of several Spies, that they have told Truth, carry them however along with you separately. You may also gain Intelligence from the People of the Country, whom Traffic or their own private Affairs draw to the Camp, or the Towns, who sometimes become Spies without knowing it, as do the prisoners, from whom also you may artfully draw Intelligence in general Conversation. The first of these, the People of the Country, should never be questioned; but artful sensible People should be employed, who, without any seeming curiosity, lead them to talk on different Subjects, and insensibly draw from them those things you want to be informed of.
   When you would know from a Prisoner what passes in the Army or Country he belongs to, send before-hand to the fame Ward, in the prison where he is to be confined, a person in whom you can trust, who speaks the Enemy’s Language, is drest in their Manner, and who in every respect bears the Marks of a Prisoner. If there are several Prisoners, they must be separated in different Wards, in each of which there should be such a person, who will draw from the Prisoners whatever you want to know, and thus you will also know how far they all agree in what they say. But it is proper to have questioned the prisoners before Hand, of what Regiment, Town, or Province they are, that the supposed Prisoner may not announce himself to be of the same, and so be discovered; for it is certain, that if the Prisoner believes the other to be really in the same Situation with himself, a very few Hours Conversation serves to draw from him every thing he knows with regard to the Army or Place where he served.
   The Spies you may have from the Monasteries in Catholic Countries are the best and surest. The Government of Consciences is a secret Empire which none can penetrate, and which penetrates every where. The Employment of this sort of Spies is infallible, where a Town is occupied by a Prince of a different Religion, or in a Country which has changed its Sovereign. Women are also serviceable either to get into a Town, to examine what passes in a Camp, or to carry Letters, because they are less suspected than Men.
You may also, in order to discover in Part what passes in the Enemy’s Country, make a Soldier desert who has Address, and in whom you can trust; who enters at one Part of the Enemy’s Frontier, and demands of the first Party of the Enemy’s Troops he meets, a Pass to take Service in any Regiment of the Army, or of any Detachment, which he knows at that time to be at the other Extremity of this Frontier, in order to observe exactly during his March all that passes, and after having arrived at the Army, and narrowly and at his Ease examined every thing, he shall again desert to your Country.
   You may also be informed of the Disposition of the Enemy’s Camp, or such other Particulars as it is important for you to be instructed in, by feigning some Pretence to send an Officer to confer with the Enemy’s General, who shall be accompanied by intelligent Persons, drest like Servants, who, while their pretended Master is in Conference with the General, on those Affairs for which he seems to be sent, shall carefully, though seemingly with Indifference, observe those things you want to be informed of.

These techniques were available not only to Washington, but to any officer who could read the original French or the English translation of this widely-printed volume. It should be no surprise, then, that George Washington was an excellent spymaster – he owned a copy of the instruction book.


[1]Military Instructions by the King of Prussia, T. Forster, trans. (London, 1762), 31-33.

[2]Maurice Count de Saxe, Reveries, or Memoirs concerning the Art of War(Edinburgh: Sands, Donaldson, Murray and Cochran, 1759), 216-218.

[3]Per the listing at

[4]Thomas Simes, The Military Guide for Young Officers(Philadelphia, 1776; originally printed London, 1772), 10-11. In this book, Simes did not cite Saxe as the source of the material on spies, but he did do so in his previous work, The Military Medley(Dublin, 1767), 169.

[5]Essay on the Art of War(London: A. Millar, Strand, 1761), 31-32.

[6]Ibid., 213-217.

One thought on “How to be a Revolutionary War Spy Master

  • Don, an excellent article highlighting Washington’s possible skills’ development through his reading. You could also have quoted Sun Tzu with similar advice, but it seems doubtful that George read Chinese.
    One small point, just to protect a reputation: when Costigin reported from New York City he had already been exchanged and no longer under the parole obligation. He had honored his officer’s oath.

Leave a Reply

Your email address will not be published. Required fields are marked *