No particular reason for this post, except that I wanted to place this excerpt on the web where people can find it.
As a Jason Isaacs fan, and therefore a fan of the character of Colonel Tavington (in The Patriot) I've read (and written) a great deal of fan-fiction based on the movie. One theme that tends to come up in Rev War fan-fiction is the woman-disguised-as-a-man hiding amongst the troops. The idea of the cross dressing Colonial-era soldier is a persistent one. However, it is invariably of a woman who dresses as a man. Put the hair a queue, find an appropriately baggy uniform (or find a tight, form-fitting pair of breeches if you're going to be in a Hollywood movie later), adopt a gruff voice and there you are.
The story of the Chevalier d'Eon is different. He was a man, a duelist and a dragoon and known to many people as such. For some reason, he began to dress as a woman. There are a number of references to him on the web, but none seem to have exactly the slant of the description below, which is an excerpt from "Benjamin Franklin, The First Civilized American" by Phillips Russell, published in 1926.
The remaining members of the Hell Fire Club seem to have been minor and undistinguished personages, but we have already said enough concerning their companions to indicate what they were like. Franklin arrived in London for his third visit too late to have been admitted to membership, the club having been dissolved when Dashwood became Lord le Despencer in 1762; but there can be little doubt that he would have rejoiced in the company of the other members almost as much as in that of his lordship. Wit, clubbability, free-thinking, and bold gallantry - these were attributes that ever fascinated the provincial Franklin.
There was another associate member or visitor to the club, who perhaps fascinated Franklin even more. This was Eon de Beaumont, known as the Chevalier d'Eon, soldier of France, writer, poet, and diplomat, the secret of whose real sex agitated for years the gossips of the chancelleries of Europe. Indeed, the Hell Fire Club once held a mock trial to determine this very point. D'Eon was living in exile in London while Franklin was there, and there is evidence that they became friends.
The mystery concerning d'Eon involved, as an old French biography puts it, "the imperious circumstances which one day compelled him to conceal his sex." What those strange circumstances were has never been authentically disclosed, but the concealment is said to have been by the order of his king, Louis XV, whose secret correspondence with the Empress Elizabeth of Russia was in charge of d'Eon for five years. Early in his career d'Eon was the secret agent and close confidant of the king, but on somehow falling out of favor, he spent an exile of 14 years in England. He was permitted to return to France in 1775.
Two years afterwards, Count Vergennes, of whose later relations with Franklin we shall presently hear, ordered d'Eon at his home in Tonnerre, to "reassume the garments of his sex." The autopsy at his death is said to have revealed d'Eon as unquestionably male.
Bearing on this point, there is a curious letter from d'Eon to Franklin in the files of the American Philosophical Society at Philadelphia. It was written in Paris in 1778, a year after Count Vergennes had issued his queer order. The following is a translation:
"I have been to Passy to have the honor of seeing you and to felicitate you on recent events occurring in America, but you were in Paris. In your absence we drank to your health and to Liberty, at the home of your friend M. le Ray de Chaumont, who was joined by madame his wife and mademoiselle his daughter in extending to me the most agreeable reception. I hope that the health of the Liberty carried by Madlle d'Eon to three places in Versailles results in all the good possible to America. My brother-in law, the Chevalier O'Gorman, has arrived from Burgundy. He will return next week. He hopes that when next spring you go to Dijon that you will give him the pleasure and honor of stopping with him at Tonnerre. I shall be very happy if I can be present at the same time and there give proofs of the sincere and respectful attachment with which I am
"Your very humble and very obedient servant,
"LA CHEVALIERE D'EON."
It is to be noted that d'Eon's signature is in the feminine. Moreover, in calling himself "servant," he uses not the usual masculine serviteur but the feminine servante.
Also, on the back of the letter there is this memorandum, apparently in Franklin's handwriting and possibly for filing purposes: "Chevaliere D'Eon, 24 jany, 1778" - again the feminine form. This letter heightens the mystery which even to this day is attached to the name of d'Eon.
To the last he dressed in women's clothes, and, clinging to his skirts, even took part in fencing duels. In his later years he was always careful to call himself, as in the above letter, "Mademoiselle d'Eon."
In connection with d'Eon there is a curious story told of Franklin during his residence as American envoy at Passy, now part of Paris but then a suburb. Franklin let it be known that he wished to contribute to the "blessed bread" being distributed in the parish of Passy. He offered thirteen brioches, or cakes, representing the thirteen American colonies, on the first of which -destined for the cure- should be inscribed, in large letters, the word "Liberty." The cure and the bishop sought to dissuade him, but it was d'Eon who caused him to renounce the project by saying: "Passy is too close to Versailles. They do not greatly care for that word there." 
It may have been that d'Eon, who at times manifested sportive inclinations, took it upon himself to carry the inscribed cakes to Versailles. If so, this would explain his reference to "the Liberty" in his letter to Franklin.
 Archives of the Historical Society of Auteuil and Passy.
Wikepedia's take: http://en.wikipedia.org/wiki/Chevalier_d'Eon
That Ben Franklin was a card, eh?