Numbers 16. Report of Surg. Jonathan Letterman, U. S. Army, Medical Director, Army of the Potomac.

HEADQUARTERS ARMY OF THE POTOMAC,
MEDICAL DIRECTOR'S OFFICE,

Camp near Culpeper Court-House, Va., October 3, 1863.

GENERAL: I have the honor to submit the following report on the operations of the medical department of this army at the battle of Gettysburg, July 1, 2, and 3: As the subject of transportation has an important bearing upon the manner in which the wounded are attended to after a battle, it is necessary to make some allusion to the manner in which this department was supplied. It is scarcely necessary to say that if the transportation is not sufficient to enable the officers of the department to conduct it properly, the effect must fall upon the wounded. In the autumn of 1862, I investigated the subject vary carefully, with the view to the adoption of some system instead of the irregular method and want of system which prior to that time was in vogue, to limit the amount necessary, and to have that amount always available. The transportation was one wagon to each regiment and one to each brigade. This gave all that was required, and it was not too much; and, it may be remarked, was a reduction of nearly one-half of that which had been in use prior to that time. This system worked well. At the battle of Chancellorsville, the department had upon the left bank of the Rappahannock means sufficient, had it been allowed to use them, for taking care of many more wounded than there came under it control. On June 19, while the army was on the march, as it were, from before Fredericksburg to some unknown point north of the Potomac River, the headquarters begin Fairfax Court-HOUSE, Va., the transportation of the department was cut down by Major-General Hooker on an average of two wagons in a brigade, in opposition to my opinion, expressed verbally and in writing. This reduction necessitated the turning in of a large portion of the supplies, tents, &c., which were necessary for the proper care of the wounded in the even of a battle. three wagons were assigned to brigade of 1, 500 men, doing away with regimental wagons. This method in its practical working is system at all, as liable to constant changes, and proved to be, what supposed at the time it would be, a failure to give the department the means necessary to conduct its operations. The Headquarters left Fairfax Court-House on June 26 ultimo, for some point as yet unknown in Maryland or Pennsylvania. On the 25th of that mont, directed Assistant Surgeon [Jeremiah B.] U. S. Army, to proceed to Washington, and obtain the supplies I had ordered the medical purveyor to have put up, and there await orders. On the 26th, he was ordered to proceed with them to Frederick. This step was taken to obviate the want of supplies consequent upon the reduction of transportation. At this it was not known that the army would be near Frederick; still, the risk had to be run, and the event justified the order, Dr. Brinton arriving at Frederick on June 28, the day the arrival of headquarters there, with twentyfive army wagon loads of such supplies as would be most required in