This particular letter  was very comprehensive and has a vast collection of previously unpublished information. I don’t believe that these letters have been published in full before, but they were re-used by McClellan in his foreword to his famous ‘Crimean’ report that followed in the next few days – those similar foreword comments were quoted by some early McClellan historians, namely, Capt. Edward Davis in his articles in ‘The Cavalry Journal’, esp. his 1916 treatise, and by Dr. James S. Hutchins, in his article published in 1970 regarding the Tojhusmuseet M1857 saddle.
This letter reveals quite a collection of new information, naming other contributors to the design, thoughts on the values of certain items, and his great admiration for Lacey & Phillips, who clearly went above and beyond to provide the best product possible.
Phila Dec 25 1856
Col H K Craig
Chief of Ordnance
There will be sent by express today or tomorrow, to your address, two boxes containing each a set of horse equipments, made under my direction by Messrs Lacey & Phillips of this city.
The tree is essentially the same in both; I had one arranged with the bare tree, at the suggestion of Capt Sacket  , the other was covered in accordance with my own original views. The advantages I claimed for this tree are: that the bars are of such a shape as to fit the horse’s back, the cantle & pommel altho sufficiently high to give all proper support to the rider, & allow a proper backing of the kit, are not in the way of the leg when mounting or dismounting, or of the bridle hand when mounted, the tree is light & strong.
The saddle bags will hold as much as, or more than the valise, and not in the way when mounting or dismounting & do not touch the horses back; the shoe pouches will be found on the saddlebags. The pouches are large enough for all that reqd to be carried, yet smaller & better shaped than those now in use; on the right pouch will be found an arrangement for carrying the camp hatchet.
I have provided no holster being of the opinion that the pistol should always be carried on the person; no carbine loop is attached, for the reason that I think the carbine should be slung over the shoulder.
For the girth I am indebted to Captain Sacket.
I have attached neither crupper or breast strap, never having found occasion to use them myself, & being of the opinion that any horse fit for cavalry service requires neither, when properly girthed.
The attachment of the girth to the flaps of the covered saddle is an idea derived from the French; I am not aware that any other part of the saddle is deduced from an foreign models. The object of attaching the girth to the flap is to bring the pressure upon the whole length of the bars, & to obtain greater simplicity.
The arrangement of the stirrups buckle is new & advantageous. The models of stirrups as submitted – all of wood, the idea ought to be carried out was to turn the stirrups in such a position as to h always ready to receive the foot; the pattern in which the eye for the leather is <thrown> [until] above the stirrup was made under a misunderstanding of the directions given – as that form affords great strength it was thought best to submit it; the second model in which the eye is below the top of the stirrups was made in accordance with the original directions; after that eventually was finished it was found that a very simple arrangement of the stirrup leather would accomplish the same purpose, with the ordinary wooden stirrup, as the last arrangement is the least expensive it will eventually be found to be the best.
The model of the shelter tent submitted is made rather larger than those in use in Europe; the material is the best that could be procured at short notice – it is submitted mainly to give the idea that with the urgent recommendation that it be adopted as part of our system.
If it is considered advantageous I can give a very simple arrangement which has suggested itself to me for making the shelter tent answer the purpose of a forage bag when necessary.
The bridle submitted is believed to be as simple as possible. The snaffle is intended to be used only as a watering bit in garrison & for the first lessons of equitation; for field service I would use the curb alone, leaving the snaffle in garrison.
If it is not deemed advisable to dispose with the snaffle and have it in the field, the arrangement permits it to be used with the curb. The bit is a modification of the Russian, its advantages will be apparent after inspection; I would recommend that it, as well as all the buckles, be made of steel & iron, then tinned.
The leather halter black is intended for use in garrison; it could probably be a better arrangement to have halter chains attached to the [ ? ], to fasten to the halter ring by a T.
Two lariats are submitted were one of leather, the other of hair; the arrangement for attaching them to the halter ring is believed to be good, whatever decision may be made with regard to the material of which the rope is made; I would prefer hair, or leather – the only objection to the latter is the reported propensity of the wolves to gnaw them – in the course of my short experience in the west I have seen many wolves, but I have never known instance of their gnawing hair lariats; the hair, however is far from this objection, is strong & easily [dried or cleaned].
I cannot pretend to say that this equipment is by any means perfect, but I feel safe in asserting that it is an important step in the right direction, that it is not a copy of any European model, & that it is a better equipment than any I saw in Europe  – it may, as far as I am concerned, best upon its own merits. It will of course be necessary to determine [upon] different types of trees, bits & c.; I would advise that a competent cavalry officer be required to determine this by actual experiment – either with the horses of a larger garrison, such as Fort Leavenworth, or at West Point, or some other suitable place.
A good place would be, on the supposition that the equipment is approved, to send a hundred sets or so to Leavenworth, fifteen or twenty to West Point, & others to large cavalry posts, & acquire immediate reports when the sizes necessary; a proper result can only be had by taking the average of a large number of horses. You will observe that the material workmanship of the specimens submitted are of the very best quality; I would recommend this as usually the most economical plan, & as the only means of issuing a really efficient equipment.
This equipment can be made by Messrs Lacy & Phillips at a rather less cost than the present Grimsley equipment, in the style of the models, while the Grimsley is of far inferior material & workmanship. As this is probably one of the last things I shall submit as an officer of the army, I naturally feel some little anxiety that it should be fairly tested; therefore, as far as I may be permitted to do so, I would respectfully argue that the trial sets be made by Messrs Lacy & Phillips, who have made the models submitted; I am fully satisfied that their work will be faithfully done, fully equal to the equipments submitted in every aspect, & that it will be for the interest of the govt to employ them. They have bestowed much time & [ ?? ] upon the models, & to them is due all the credits, if any there be, of carrying out my ideas as to a proper cavalry equipment.
The actual cost incurred for making the two sets will (the word ‘probably’ lined out) be more than the amount authorized by the Dept; if the model is approved I presume the Dept will be willing to authorize the additional expenditure; if the model is not approved I am of course prepared to pay the excess of cost myself.
I am after undertaking the matter I found that many of the first experiments as to trees had to be revised & done away with, as I desired to submit a really good equipment. I preferred taking upon myself [responsibility] the additional expense, & have no complaint made if the Dept does not see fit to authorize it, when I have acted with a full knowledge of the instructions not to .
I am abt srv
Geo B McC
Sources/Notes: Library of Congress, George Brinton McClellan Papers: Correspondence II, 1823-1898; 1856, Sept. 28-1857, Feb. 14, Image 32
 Capt. Delos Bennett Sackett, 1st Cavalry – then on detached duty as member of Board to Revise Army Regulations, Washington, D. C.
 This phrase was used in other communications from McClellan, namely when he submitted his Report to the Secretary of War some days after this letter.