accompanied me through the trying campaign of the Peninsula, and frequently rendered important services. Of these officers Captain McMahon was assigned to the personal staff of Brigadier General Franklin, and Captains Kirkland and Mason to that of Brigadier General F. J. Porter during the siege of Yorktown. They remained subsequently with those general officers. Major LeCompte left the army during the siege of Yorktown; Colonels Gantt and Astor, Major Russell, Captains L. P. D'Orleans, R. D'Orleans, and Raymond at the close of the Peninsula campaign. Before its termination Captains W. S. Abert and Charles R. Lowell, of the 6th United States cavalry, joined my staff as aides-de-camp, and remained with me until I was relieved from the command of the army of the Potomac. All of these officers served me with great gallantry and devotion; they were ever ready to execute any service, no matter how dangerous, difficult, or fatiguing.

ENGINEERS.

When I assumed command of the army of the Potomac I found Major J. G. Barnard, United States engineers, subsequently brigadier general of volunteers, occupying the position of chief engineer of that army. I continued him in the same office, and at once gave the necessary instructions for the completion of the defences of the capital, and for the entire reorganization of the department.

Under his direction the entire system of defences was carried into execution. This was completed before the army departed for Fort Monroe, and is a sufficient evidence of the skill of the engineers and the diligent labor of the troops.

For some months after the organization of the army of the Potomac was commenced there were no engineer troops with it. At length, however, three companies were assigned. Under the skilful management of Captain J. C. Duane, United States engineers, these new companies rapidly became efficient, and, as will be seen, rendered most valuable service during the ensuing campaigns.

The number of engineer troops being entirely inadequate to the necessities of the army, an effort was made to partially remedy this defect by detailing the 15th and 50th New York volunteers, which contained many sailors and mechanics, as engineer troops. They were first placed under the immediate superintendence of Lieutenant Colonel B. S. Alexander, United States engineers, by whom they were instructed in the duties of pontoniers, and became somewhat familiar with those of sappers and miners. Previous to the movement of the army for the Peninsula this brigade was placed under the command of Brigadier General D. P. Woodbury, major United States engineers.

The labor of preparing the engineer and bridge trains devolved chiefly upon Captain Duane, who was instructed to procure the new model French bridge train, as I was satisfied that the India-rubber pontoon was entirely useless for the general purposes of a campaign.

The engineer department presented the following complete organization when the army moved for the Peninsula :

Brigadier General J. G. Barnard, chief engineer; First Lieutenant H. C. Abbott, topographical engineers, aide-de-camp. Brigade volunteer engineers, Brigadier General Woodbury commanding: 15th New York volunteers, Colonel McLeod Murphy; 50th New York volunteers, Colonel C. B. Stewart. Battalion, three companies United States engineers, Captain J. C. Duane commanding; companies respectively commanded by First Lieutenants C. B. Reese, C. E. Cross, and O. E. Babcock, United States engineers. The chief engineer was ably assisted in his duties by Lieutenant Colonel B. S. Alexander, and First Lieutenants C. R. Comstock, M. D. McAlester, and Merrill, United States engineers. Captain C. S. Stuart and Second Lieutenant F. U. Farquhar, United States engineers, joined after the army arrived at Fort Monroe.

The necessary bridge equipage for the operations of a large army had been

collected, consisting of bateaux with the anchors and flooring material, (French model,) trestles, and engineers' tools, with the necessary wagons for their transportation.

The small number of officers of this corps available rendered it impracticable to detail engineers permanently at the headquarters of corps and divisions. The companies of regular engineers never had their proper number of officers, and it was necessary, as a rule, to follow the principle of detailing engineer officers temporarily whenever their services were required.

TOPOGRAPHICAL ENGINEERS.

To the corps of topographical engineers was intrusted the collection of topographical information and the preparation of campaign maps. Until a short time previous to the departure of the army for Fort Monroe, Lieutenant Colonel John W. Macomb was in charge of this department, and prepared a large amount of valuable material. He was succeeded by Brigadier General A. A. Humphreys, who retained the position throughout the Peninsula campaign. These officers were assisted by Lieutenants H. L. Abbott, O. G. Wagner, N. Bowen, John M. Wilson, and James H. Wilson, topographical engineers. This number, being the greatest available, was so small that much of the duty of the department devolved upon parties furnished by Professor Bache, Superintendent of the Coast Survey, and other gentlemen from civil life.

Owing to the entire absence of reliable topographical maps, the labors of this corps were difficult and arduous in the extreme. Notwithstanding the energy and ability displayed by General Humphreys, Lieutenant Colonel Macomb, and their subordinates, who frequently obtained the necessary information under fire, the movements of the army were sometimes unavoidably delayed by the difficulty of obtaining knowledge of the country in advance. The result of their labors has been the preparation of an excellent series of maps, which will be invaluable to any army traversing the same ground.

During the campaign it was impossible to draw a distinct line of demarcation between the duties of the two corps of engineers so that the labors of reconnoissances of roads, of lines of intrenchments, of fields for battle, and of the position of the enemy, as well as the construction of siege and defensive works, were habitually performed by details from either corps, as the convenience of the service demanded.

I desire to express my high appreciation of the skill, gallantry, and devotion displayed by the officers of both corps of engineers, under the most trying cir

cumstances.

During the Maryland campaign I united the two corps under Captain J. C. Duane, United States engineers, and found great advantages from the arrangement.

MEDICAL DEPARTMENT.

For the operations of the medical department I refer to the reports, transmitted herewith, of Surgeon Charles S. Tripler and Surgeon Jonathan Letterman, who, in turn, performed the duties of medical director of the army of the Potomac, the former from August 12, 1861, until July 1, 1862, and the latter after that date. The difficulties to be overcome in organizing and making effective the medical department were very great, arising principally from the inexperience of the regimental medical officers, many of whom were physicians taken suddenly from civil life, who, according to Surgeon Tripler, "had to be instructed in their duties from the very alphabet," and from the ignorance of the line officers as to their relations with the medical officers, which gave rise to confusion and conflict of authority. Boards of examination were instituted, by which many ignorant officers were removed; and by the successive exertions of Surgeons Tripler and Letterman, the medical corps was brought to a very high

degree of efficiency. With regard to the sanitary condition of the army while on the Potomac, Dr. Tripler says that the records show a constantly increasing immunity from disease. "In October and November, 1861, with an army averaging 130,000 men, we had 7,932 cases of fever of all sorts; of these, about 1,000 were reported as cases of typhoid fever. I know that errors of diagnosis were frequently committed, and therefore this must be considered as the limit of typhoid cases. If any army in the world can show such a record as this, I do not know when or where it was assembled." From September, 1861, to February, 1862, while the army was increasing, the number of sick decreased from 7 per cent. to 6.18 per cent. Of these, the men sick in the regimental and general hospitals were less than one-half; the remainder were slight cases, under treatment in quarters. "During this time, so far as rumor was concerned, the army was being decimated by disease every month." Of the sanitary condition of the army during the Peninsula campaign, up to its arrival at Harrison's landing, Dr. Tripler says: "During this campaign the army was favored with excellent health. No epidemic disease appeared. Those scourges of modern armies--dysentery, tupus, cholera-were almost unknown. We had some typhoid fever and more malarial fevers, but even these never prevailed to such an extent as to create any alarm. The sick reports were sometimes larger than we cared to have them; but the great majority of the cases reported were such as did not threaten life or permanent disability. I regret that I have not before me the retained copies of the monthly reports, so that I might give accurate statistics. I have endeavored to recover them, but have been unsuccessful. My recollection is, that the whole sick report never exceeded 8 per cent. of the force, and this including all sorts of cases, the trivial as well as the severe. The army of the Potomac must be conceded to have been the most healthy army in the service of the United States."

His remarks at the conclusion of his report upon our system of medical administration, and his suggestions for its improvement, are especially worthy

of attention.

The service, labors, and privations of the troops during the seven days' battles had, of course, a great effect on the health of the army, after it reached Harrison's landing, increasing the number of sick to about 20 per cent. of the whole force.

The nature of the military operations had also unavoidably placed the medical department in a very unsatisfactory condition. Supplies had been almost entirely exhausted or necessarily abandoned; hospital tents abandoned or destroyed, and the medical officers deficient in numbers and broken down by fatigue.

All the remarkable energy and ability of Surgeon Letterman were required to restore the efficiency of his department; but before we left Harrison's landing he had succeeded in fitting it out thoroughly with the supplies it required, and the health of the army was vastly improved by the sanitary measures which were enforced at his suggestion.

The great haste with which the army was removed from the Peninsula made it necessary to leave at Fort Monroe, to be forwarded afterwards, nearly all the baggage and transportation, including medical stores and ambulances, all the vessels being required to transport the troops themselves and their ammunition ; and when the army of the Potomac returned to Washington after General Pope's campaign, and the medical department came once more under Surgeon Letterman's control, he found it in a deplorable condition. The officers were worn out by the labors they had performed, and the few supplies that had been brought from the Peninsula had been exhausted or abandoned, so that the work of reorganization and resupplying had to be again performed, and this while the army was moving rapidly, and almost in the face of the enemy. That it was successfully accomplished is shown by the care and attention which the wounded received after the battles of South Mountain and Antietam.

Among the improvements introduced into his department by Surgeon Letterman, the principal are the organization of an ambulance corps, the system of field hospitals, and the method of supplying by brigades, all of which were instituted during the Maryland campaign, and have since proved very efficient.

QUARTERMASTER'S DEPARTMENT.

On assuming command of the troops in and around Washington, I appointed Captain S. Van Vliet, assistant quartermaster, (afterwards brigadier general,) chief quartermaster to my command, and gave him the necessary instructions for organizing his department, and collecting the supplies requisite for the large army then called for.

The disaster at Manassas had but recently occurred, and the army was quite destitute of quartermaster's stores. General Van Vliet, with great energy and zeal, set himself about the task of furnishing the supplies immediately necessary, and preparing to obtain the still larger amounts which would be required by the new troops, which were moving in large numbers towards the capital. The principal depot for supplies in the city of Washington was under charge of Colonel D. H. Rucker, assistant quartermaster, who ably performed his duties. Lieutenant Colonel R. Ingalls, assistant quartermaster, was placed in charge of the department on the south side of the Potomac. I directed a large depot for transportation to be established at Perryville, on the left bank of the Susquehanna, a point equally accessible by rail and water. Captain C. G. Sawtelle, assistant quartermaster, was detailed to organize the camp, and performed his duties to my entire satisfaction. Captain J. J. Dana, assistant quartermaster, had immediate charge of the transportation in and about Washington, as well as of the large number of horses purchased for the use of the artillery and cavalry. The principal difficulties which General Van Vliet had to encounter arose from the inexperience of the majority of the officers of his department in the new regiments and brigades.

The necessity of attending personally to minor details rendered his duties arduous and harassing in the extreme. All obstacles, however, were surmounted by the untiring industry of the chief quartermaster and his immediate subordinates, and when the army was prepared to move the organization of the department was found to be admirable.

When it was determined to move the army to the Peninsula, the duties of providing water transportation were devolved by the Secretary of War upon his assistant, the Hon. John Tucker. The vessels were ordered to Alexandria, and Lieutenant Colonel Ingalls was placed in immediate charge of the embarkation of the troops, transportation, and material of every description. Operations of this nature, on so extensive a scale, had no parallel in the history of our country.

The arrangements of Lieutenant Colonel Ingalls were perfected with remarkable skill and energy, and the army and its materiel were embarked and transported to Fortress Monroe in a very short space of time, and entirely without loss.

During the operations on the Peninsula, until the arrival of troops at Harrison's landing, General Van Vliet retained the position of chief quartermaster, and maintained the thorough organization and efficiency of his department. The principal depots of supplies were under the immediate charge of Lieutenant Colonels Ingalls and Sawtelle.

On the 10th of July, 1862, General Van Vliet having requested to be relieved from duty with the army of the Potomac, I appointed Lieutenant Colonel Ingalls chief quartermaster, and he continued to discharge the duties of that office during the remainder of the Peninsula and the Maryland campaigns in a manner which fully sustained the high reputation he had previously acquired.

The immediate amount of labor accomplished, often under the most difficult circumstances, the admirable system under which the duties of the department were performed, and the entire success which attended the efforts to supply so large an army, reflect the highest credit upon the officers upon whom these onerous duties devolved. The reports of General Van Vliet and Lieutenant Colonel Ingalls, with the accompanying documents, give in detail the history of the department from its organization until I was relieved from the command of the army of the Potomac.

SUBSISTENCE DEPARTMENT.

On the 1st of August, 1861, Colonel H. F. Clark, commissary of subsistence, joined my staff, and at once entered upon his duties as chief commissary of the army of the Potomac. In order to realize the responsibilities pertaining to this office, as well as to form a proper estimate of the vast amount of labor which must necessarily devolve upon its occupant, it is only necessary to consider the unprepared state of the country to engage in a war of such magnitude as the present, and the lack of practical knowledge, on the part of the officers, with reference to supplying and subsisting a large, and at that time, unorganized army. Yet, notwithstanding the existence of these great obstacles, the manner in which the duties of the commissary department were discharged was such as to merit and call forth the commendation of the entire army.

During the stay of the army of the Potomac in the vicinity of Washington, prior to the Peninsula campaign, its subsistence was drawn chiefly from the depots which had been established by the commissary department at Washington, Alexandria, Forts Corcoran and Runyon. In the important task of designating and establishing depots of supplies, Colonel Clarke was ably seconded by his assistants, Colonel Amos Beckwith, commissary of subsistence, U. S. A.; Lieutenant Colonel George Bell, commissary of subsistence, U. S. A.; Lieutenant Colonel A. P. Porter, commissary of subsistence, U. S. A.; Captain Thomas Wilson, commissary of subsistence, U. S. A.; Captain Brownell Granger, commissary of subsistence, U. S. volunteers; Captain W. H. Bell, commissary of subsistence, U. S. A.; Captain J. H. Woodward, commissary of subsistence, U. S. volunteers; and Captain W. R. Murphy, commissary of subsistence, U. S. volunteers.

For a full knowledge of the highly creditable manner in whic heach and all of the above-mentioned officers discharged their duties, I invite attention to the detailed report of Colonel Clarke. The remarks and suggestions contained in his report are worthy of attention, as affording valuable rules for the future guidance of the subsistence department in supplying armies in the field. The success of the subsistence department of the army of the Potomac was in a great measure attributable to the fact that the subsistence department at Washington made ample provision for sending supplies to the Peninsula, and that it always exercised the most intelligent foresight. It moreover gave its advice and countenance to the officers charged with its duties and reputation in the field, and those officers, I am happy to say, worked with it, and together, in perfect harmony for the public good. During the entire period that I was in command of the army of the Potomac there was no instance within my knowledge where the troops were without their rations from any fault of the officers of this department.

ORDNANCE DEPARTMENT.

This very important branch of the service was placed under the charge of Captain C. P. Kingsbury, ordnance corps, colonel and aide-de-camp. Great difficulty existed in the proper organization of the department for the want of a sufficient number of suitable officers to perform the duties at the various head