Duportail’s sketch of the defenses of Valley Forge. Courtesy Cornell University Library, https://digital.library.cornell.edu/catalog/ss:545278.
Duportail was staying on the farm of a Welsh Quaker named John Havard Jr. at Chesterbrook at the time. The house came to be known as the Duportail House. General Duportail’s original map of the Valley Forge defenses was found in the attic rafters during renovations in 1903 and has been in the collections of the Pennsylvania Historical Society since 1908.
SAPPERS AND MINERS
Duportail also proposed to supplement the engineer officers with companies of combat engineers and called them companies of sappers and miners, according to European custom. The sappers dug the entrenchments (saps) for a formal siege; the miners constructed underground tunnels. These companies, which would become a permanent part of the Continental Army, could execute small projects or supervise infantry details in more extensive undertakings. Duportail submitted the paper to the commander in chief about January 18, 1778:
If fortification is necessary in any Armies, it is peculiarly so in those, which like ours, from a deficiency in the practice of manoeuvres cannot oppose any to those of the enemy being necessitated therefore to receive him on their own ground, they ought always to be protected either by a natural or artificial Fortification, if it were only to have (under favor of the resistance of this fortification) sufficient time to ascertain the Result of the Enemy’s movements—where his principal force is directed—and where his greatest effort is to be made. With respect to natural fortification, all Situations do not afford it—and to rely entirely upon it, would involve prodigious restraint in the choice of Positions and exclude many excellent ones considered relatively to the operations of War—it is therefore much more advantageous to have recourse to artificial Fortification which is applicable in all Situations.
The very great difficulties which I experienced in the last Campaign, both in setting on foot the most simple work and having it executed with the necessary Conditions, induce me to propose to His Excellency an establishment which is absolutely indispensable, if he chooses to derive hereafter those succours from Fortification which it holds out to him.
I would desire to have three Companies of Sappers formed—they should be instructed in every thing that relates to the construction of Field works—how to dispose of the Earth to cut the Slopes—face with Turf or Sods—make fascines—arrange them properly—cut and fix Palisades &ct.
The Sappers should be distributed in the different works, and a sufficient number of fatigue men drawn from the line should be joined to them to work under their direction, by which means the work would be executed with a perfection and celerity which otherwise will ever be unknown in this army—it is, I believe, altogether useless to enlarge upon a matter so obvious—I proceed therefore immediately to the principal Conditions on which the Corps should be formed.
1st. The pay ought to be greater than that of ordinary foot soldiers because the Service is exceedingly hard—this is the practice in Europe, and they receive besides extraordinary pay when they work.—Choice ought to be made of vigorous Soldiers and the preference should be given to Carpenters and Masons.
2. The Non-commissioned officers ought all to read and write, and be intelligent persons of good Characters.
3. The Companies of Sappers ought to be altogether under the Command of the Head Engineer—for if the Major Generals had a right to employ them as they pleased, each, from a desire of fortifying his Camp in his own way, would ask for Sappers and they would all be taken from the Engineers.
Besides as such partial works do not enter into the general plan of the position they are for the most part useless, ill concerted, and sometimes even dangerous.
4. The Captains of Sappers will be charged with the detail of their Companies, and each of them will be accountable to the Commanding officer of the Engineers in order that he may always know the State of the Companies, their Strength etc.
5. Each Company should always have its Tools with it, carried on a Waggon provided for the purpose—The Company should be answerable for all Tools lost—and in case any should be broke, the pieces are to be produced to the Officer to whom the detail of the Company is to be committed.
The Camp of the Sappers to be assigned by the Commanding officer of Engineers adjacent to the place where they are to be employed.
Of the Officers.
If it be important to choose the Privates in these Companies—it is much more so to choose the Officers—The Congress ought, in my opinion, to think of forming Engineers in this Country to replace us when we shall be called home—The Companies of Sappers now proposed might serve as a School to them—they might there acquire at once the practical part of the Construction of Works, and if choice be made of young men, well bred, intelligent and fond of Instruction, we shall take pleasure in giving them principles upon the choice of Situations, and the methods of adapting works to the ground.
If His Excellency approves my Plan—I would advise the speedy execution of it—in order that the Companies may have served their Apprenticeship before the opening of the Campaign.
These Companies ought not to be composed of Recruits—but Soldiers answering the description above should be taken from the Line for the purpose.
While I am employed in representing the defects of my branch of the Army—I entreat His Excellency to observe that four Engineers are not sufficient—of the four, one is always detached and sometimes two, which is the case at present—and I am left with only one Officer—it is impossible for us to do the Service of the Army. There is at York Town a French officer who was
