- Organization of the Army -- what an Army is -- infantry, artillery, cavalry, engineer troops -- the staff and its departments -- details of the creation of the Army of the Potomac.
The organized armies of modern times consist of two well-defined parts: the fighting force, or “line,” and “the staff,” which directs, inspects, and supplies the former. The line is made up of infantry, artillery, cavalry, and engineer troops. As infantry can move wherever a man can set his foot, can fight on all kinds of ground, gives the most destructive fire of all the arms, and is the least expensive and most easily instructed, it constitutes the great bulk of all large armies, and is decidedly the most important. With equally good generals, that army which has the best infantry is pretty sure to win, for no reasonable superiority in the other arms of service can compensate for marked inferiority in the infantry. The essential qualities of good infantry are: the ability to make long marches, with their full equipment, without straggling; accuracy of fire; confidence in their ability to use the bayonet — for this will prevent their breaking upon the very near approach of a hostile line — coolness, intelligence, determination, and mutual confidence in attacking or receiving an attack; the ability to reform rapidly after a successful attack, and to rally when driven back, either after a repulsed attack or when obliged to retreat from a defensive position; the power of enduring fatigue, exposure, and hunger. Next in importance is the artillery, whose work it is to open the way for, and cover the movements of, the other arms by destroying the enemy's defences at long range, silencing his artillery, and demoralizing his infantry; or, at short ranges, to crush them by a rapid fire of case and shrapnel. It is also a part of its duty to cover the retreat of beaten infantry, and to assist in the operations of detached bodies of cavalry.  There is thus heavy artillery, whose business it is to handle siege-guns and those used in permanent defences, and field-artillery, who accompany an army in the field. Field-artillery is made up of three kinds — viz., the mounted batteries, whose cannoneers usually march on foot, but during rapid movements ride upon the carriages and caissons, and which serve with the regiment, division, and army corps; the horse-batteries, whose cannoneers are provided with saddle-horses, and which are especially intended for service with the cavalry; and the batteries of position, consisting of the heaviest field-guns, intended especially for action against the enemy's material defences. The field-guns, at the period of which I write, were generally provided in the ratio of at least two and a half guns to each thousand infantry, and three or four guns to each thousand cavalry, the exact proportion depending somewhat on the nature of the field of war and the quality of the troops. With raw troops a somewhat larger proportion is necessary than with veterans. The technical information necessary for the artillery officers and men renders it difficult to improvise thoroughly efficient artillery. The cavalry is an indispensable part of every army. It not only takes part, as occasion demands, in general battles, but, with a due proportion of horse-artillery, is capable of independent action, even at long distances from the main body of the army. Upon it devolves to a great extent the duty of observing and discovering the positions, movements, and strength of the enemy, as well as masking those of its own army. It is capable of making extensive inroads into the enemy's country, and is usually employed to threaten and attack his communications, supply-trains, etc. The modern improvements in firearms have certainly affected the employment of cavalry on the field of battle against infantry and artillery, but have not lessened the importance of its other duties. Nor is it probable that the number of these arms will in the future be materially diminished. The employment of breech-loading small arms has added very much to the strength of cavalry, and it is certain that in future wars large bodies of cavalry will be employed as mounted infantry. That is, they will use their horses to move rapidly to the point of action, and fight on foot. Under ordinary circumstances it has usually been regarded  as advisable to furnish cavalry to the extent of one-sixth to one-eighth of the infantry force. To render cavalry efficient it is necessary that the officers and men should be of a superior order of intelligence, and that they should fully understand the care of their horses, which should be active and enduring. Officers and men should be excellent horsemen, skilful in the use of their weapons, and thoroughly instructed in the work of reconnoissance. It is really much more difficult to form reliable cavalry at short notice than to instruct artillery and infantry. It is the duty of engineer troops to conduct siege operations; to supervise and construct temporary defences and the works for their attack; to construct, repair, and destroy bridges of all kinds, fords, roads, etc. The repair and destruction of railways should also be under their direction. The performance of these duties requires a superior order of men, skilled in some mechanical trade, and needs careful instruction. In ordinary cases the engineer troops should number about one-fortieth of the infantry. To direct the movements and supply the wants of the combatants is the business of the staff which in modern armies is a complicated and extensive organization. It includes:
In large armies, with numerous staff corps charged with such manifold and important duties, it has been found necessary to establish the position of chief of staff, who might supervise and co-ordinate the various branches, and thus relieve the commanding general from a multiplicity of detail. This office, found in all European armies, had never been established in our own. I soon found it necessary for the Army of the Potomac. The officer holding such a confidential relation with his commander should always be a man possessing the latter's entire confidence. I therefore selected for this place Col. R. B. Marcy, inspector-general of the army, whose rank was also superior to that of all the staff officers on duty with the Army of the Potomac. My orders for the movements and fighting of the troops were generally issued through the chief of staff. One of my earliest measures was the formation of permanent brigades of infantry. The new levies of infantry, upon their arrival in Washington, were formed into provisional brigades and placed in camps in the suburbs on the Maryland  side of the river, for equipment, instruction, and discipline. As soon as regiments were in fit condition for transfer to the forces across the Potomac they were assigned to the brigades serving there. Brig.-Gen. F. J. Porter was at first assigned to the charge of the provisional brigades. Brig.-Gen. A. E. Burnside was the next officer assigned this duty, from which, however, he was soon relieved by Brig.-Gen. Casey, who continued in charge of the newly arriving regiments until the Army of the Potomac departed for the Peninsula, in March, 1862. The newly arriving artillery troops reported to Brig.-Gen. William F. Barry, the chief of artillery, and the cavalry to Brig.-Gen. George Stoneman, the chief of cavalry, and were also retained on the Maryland side until their equipment and armament were essentially completed and some rudimentary instruction obtained. A few days after reaching Washington Gen. Scott asked me what I intended to do in the way of organization. I replied that I wished the force under my command to be organized as and denominated an army instead of a geographical division; that I should first form brigades, then divisions, and, when in the field, army corps. My reason for postponing the formation of the latter was that with untried general officers it would be too dangerous an experiment to appoint any to such high and important commands without first proving them in actual campaign and in battle. He objected to all I proposed, save the brigade formation, saying that under our system and regulations it would be impossible to administer the affairs of an “army,” and that the retention of the system and nomenclature of geographical divisions and departments was an absolute necessity; he also objected to the formation of divisions as unnecessary, for the reason that in Mexico he had only brigades. I called to his attention the fact that, all the world over, fighting forces were organized as armies; that I had done so in West Virginia; and that his force in Mexico was a very small affair in comparison with that soon to be collected in front of Washington. He did not change his views. So I quietly went to work in my own way. The result was that on the 20th of Aug. the order constituting the Army of the Potomac was issued; and in addition to the two departments originally under my command, the troops in the Shenandoah, Maryland, and Delaware  were also included in the Army of the Potomac, the old departments being broken up and merged in the newly created army. Thus I had command of all the troops on the line of the Potomac and as far to the rear as Baltimore and Fort Delaware. During the first days of August I procured the passage of an act authorizing the appointment of additional aides-de-camp to general officers; these might be taken from civil life or from the army, and were to be of no higher grade than that of colonel. I used this lam not only to furnish the requisite number of actual aides-de-camp, but also to give additional pay and rank in the regular army to officers whose duty made such a step necessary. For instance, I gave to Maj. Barry, chief of artillery, and to Maj. H. J. Hunt, commanding the reserve artillery, the grade of colonel; to Van Vliet and Clarke the same. When the organization of the brigades was well established, and the troops somewhat disciplined and instructed, divisions of three brigades each were gradually formed. I intended to compose each division of three infantry brigades of four regiments each, four batteries, and one regiment of cavalry, which would have given a nominal strength of 12,000 infantry, 1,000 cavalry, and 24 guns, or an effective of about 10,000 infantry, 700 cavalry, and 24 guns. It was determined to collect whatever regular infantry could be obtained to form the nucleus of a reserve. The measures taken for recruiting these regiments were so insufficient and the results so meagre that as late as the 30th of April, 1862, there were only 4,600 men in the 71 companies, regular infantry, on duty with the Army of the Potomac. These, together with the 5th and 10th N. Y. Volunteers, finally formed part of the 5th corps as a division under Brig.-Gen. Sykes, 3d U. S. Infantry. The creation of an adequate artillery establishment for an army of so large proportions was a formidable undertaking; and had it not been that the country possessed in the regular service a body of accomplished and energetic artillery officers, the task would have been almost hopeless. The charge of organizing this most important arm was confided to Maj. (afterwards Brig.-Gen.) William F. Barry, chief of artillery, whose industry and zeal achieved the best results The following principles were adopted as the basis of organization:  1. That the proportion of artillery should be in the proportion of at least two and one-half pieces to 1,000 men, to be expanded, if possible, to three pieces to 1,000 men. 2. That the proportion of rifled guns should be restricted to the system of the United States ordnance department; and of Parrott and the “smooth-bores” (with the exception of a few howitzers for special service) to be exclusively the 12-pounder gun, of the model of 1857, variously called the “gun-howitzer,” the “light twelve-pounder,” or the “Napoleon.” 3. That each field-battery should, if practicable, be composed of six guns, and none to be less than four guns, and in all cases the guns of each battery should be of uniform calibre. 4. That the field-batteries were to be assigned to divisions, and not to brigades, and in the proportion of four to each division, of which one was to be a battery of regulars, the remainder of volunteers, the captain of the regular battery to be the commandant of artillery of the division. In the event of several divisions constituting an army corps, at least one-half of the divisional artillery was to constitute the reserve artillery of the corps. 5. That the artillery reserve of the whole army should consist of 100 guns, and should comprise, besides a sufficient number of light “mounted batteries,” all the guns of position, and, until the cavalry were massed, all the horse-artillery. 6. That the amount of ammunition to accompany field-batteries was not to be less than 400 rounds per gun. 7. A siege-train of 50 pieces. This was subsequently expanded, for special service at the siege of Yorktown, to very nearly 100 pieces, and comprised the unusual calibres and enormously heavy weight of metal of two 200-pounders, five 100-pounders, and ten 13-inch sea-coast mortars. As has been before stated, the whole of the field-artillery of the Army of the Potomac, July 28, 1861, was comprised of 9 imperfectly equipped batteries of 30 guns, 650 men, and 400 horses. In March, 1862, when the whole army took the field, it consisted of 92 batteries of 520 guns, 12,500 men, and 11,000 horses, fully equipped and in readiness for active field service; of the whole force 30 batteries were regulars and 62 batteries volunteers. During the short period of seven months all of this immense amount of material was manufactured or purchased, and issued by the ordnance department and placed in the hands of the artillery  troops after their arrival in Washington. About one-fourth of all the volunteer batteries brought with them from their respective States a few guns and carriages, but they were nearly all of such peculiar calibre as to lack uniformity with the more modern and more serviceable ordnance with which the other batteries were armed, and they therefore had to be withdrawn and replaced by more suitable material. While about one-sixth came supplied with horses and harness, less than one-tenth were apparently fully equipped for service when they reported; and every one even of these required the supply of many deficiencies of material, and very extensive instruction in the theory and practice of their special arm. The operations on the Peninsula by the Army of the Potomac commenced with a full field-artillery force of 49 batteries of 274 guns. To this must be added the field-artillery of Franklin's division of McDowell's corps, which joined a few days before the capture of Yorktown, but was not disembarked from its transports for service until after the battle of Williamsburg, and the field-artillery of McCall's division of McDowell's corps (4 batteries, 22 guns), which joined in June, a few days before the battle of Mechanicsville (June 26, 1862), making a grand total of field-artillery at any time with the army of the peninsula of 57 batteries of 318 guns. When there were so many newly organized volunteer field-batteries, many of whom received their first and only instruction in the entrenched camps covering Washington during the three or four inclement months of the winter of 1861-62, there was, of course, much to be improved. Many of the volunteer batteries, however, evinced such zeal and intelligence, and availed themselves so industriously of the instructions of the regular officers, their commanders, and the example of the regular batteries, their associates, that they made rapid progress and attained a degree of proficiency highly creditable. Gen. Barry served as chief of artillery with the Army of the Potomac until the close of the Peninsular campaign; he performed his duties with great zeal, patience, and ability. The artillery reserve was originally commanded by Col. H. J. Hunt, who gave up the command only when appointed chief of artillery in place of Gen. Barry. The artillery reserve was then commanded by Col. George W. Getty, an excellent officer.  Gen. Hunt retained the position of chief of artillery until the close of the war. I regarded him as the best living commander of field-artillery. He was a man of the utmost coolness in danger, thoroughly versed in his profession, an admirable organizer, a soldier of a very high order. As I write this (July, 1882) Hunt is likely to be retired as a colonel — a man whose services in any other army would have been rewarded by titles, high rank, and ample pension. He is one of the most marked instances within my knowledge of the highest merit and services passed over unacknowledged and unrewarded. Hunt's merits consisted not only in organizing his command to the best advantage, but in using it on the field of battle with the utmost skill and power. The services of this most distinguished officer in reorganizing and refitting the batteries prior to and after Antietam, his gallant and skilful conduct on that field, at Malvern, and in fact during the whole Peninsular campaign, merit the highest encomiums in my power to bestow. The country in which operations were to be conducted was so obstructed by forests as to present few favorable opportunities for the employment of long-range artillery. I therefore desired to compose the artillery two-thirds of the Napoleon gun — a light 12-pounder-and one-third of rifled guns. But the facilities for the construction of army guns were so limited, while those for iron guns were comparatively so great, that in the first armament it was impossible to observe these proportions, so that when the army took the field less than one-third were Napoleon guns, and it was only during the reorganization for the Antietam campaign that it was possible to approach the proportions originally fixed upon. Our experience in battle proved the correctness of these views. The shrapnel and canister from the Napoleons was always most destructive to the hostile infantry at close range. We seldom saw the enemy at long range in large bodies. On the 20th of Aug., 1861, I had 80 guns. The returns of Oct. 15 show that there were 27 batteries of divisional artillery. Of these 17 were regulars and 10 volunteers, and, as several had only 4 guns, there were not more than 140 guns in all, and of these the rifled guns composed a good deal more than two-thirds. Including Banks and Dix, there were 33 batteries, of which 19 regulars and 14 volunteers, making not over 168 guns in all, to a force of 143,647 present on Oct. 15, and out of these guns must  be provided those required for the garrisons of Washington and Baltimore, and the defences of the line of the Potomac. In regard to the 140 guns, they belonged to a force of about 120,000 men, and out of the number would come those required for the garrison of Washington and the defences of the Potomac. It was not until after this date that artillery material and equipment flowed in with any considerable rapidity, so that, even disregarding the question of instruction, it was not until after the season for active operations had passed that a sufficient number of equipped batteries were disposable to finish the requisite reserve and divisional artillery. The mass of the artillery was not in condition to move until the following April, and even then several of the volunteer batteries were deficient in instruction. The difficulties attending the organization of a suitable cavalry force were very great, and it cannot be said that they were ever satisfactorily overcome. The newly arriving regiments reported to Gen. Stoneman, the chief of cavalry, and, as with the artillery and infantry, were, as far as circumstances would permit, retained for a certain time on the north bank of the Potomac. There was at first a total lack of equipment for the cavalry, and it was very long before this difficulty was removed. So great was the lack of cavalry arms that I was obliged to organize Rush's regiment (6th Penn.) as lancers, it being impossible to provide other weapons. Many of the officers and men were quite ignorant of the management of horses, and could not even ride well. Moreover, there was too little appreciation on the part of the government of the necessity and advantages of that arm of service. With the cavalry, as with the other arms of service, every effort was made to weed out inefficient and incompetent officers by means of courts-martial and boards of examination. As rapidly as possible every cavalry soldier was armed with a sabre and revolver, and at least two squadrons in each regiment with the carbine.1 It was intended to assign at least one regiment of cavalry to each infantry division so long as the division organization was the highest, and, when army corps should be formed, to attach  a strong brigade of cavalry to its headquarters, leaving with the division only enough for the necessary duty; also to form a general cavalry reserve. On the 15th of Oct. there were serving with the Army of the Potomac, including General Banks's command, one regiment and two companies of regular cavalry, and eleven regiments of volunteer cavalry. When the army took the field there were on its rolls four regiments and two companies of regular cavalry, eighteen regiments and five companies of volunteer cavalry, besides four regiments yet unprovided with horses. Of these there went to the Peninsula the regulars and four regiments and five companies of volunteers, making eight regiments and seven companies; and there remained with Gen. Banks and at Washington twenty-one regiments, besides the four unprovided with horses. Circumstances beyond my control rendered it impossible for me to carry out my views as to the cavalry, and it was entirely against my wishes and judgment that I was left in the field with so small a force of this arm. Of the field force one regiment of regulars were necessarily employed on provost duty, and two companies of regulars and one of volunteers at headquarters, leaving only three regiments of regulars and four regiments and four companies of volunteers, certainly not over four thousand men at most, to do all the cavalry and mounted orderly duty for the army of eleven divisions — a force so ridiculously insufficient, less than one-fourth of what it should have been, as to render it strange that the enemy contented themselves with riding around our lines only once on the Peninsula. As there were but three weak companies of engineer troops available, I did the best in my power to supply the deficiency by detailing as volunteer engineer troops the 15th and 50th N. Y. Volunteers, which comprised an unusual number of sailors and mechanics in their ranks. These were formed into an engineer brigade, and placed under the command, first of Col. E. S. Alexander, U. S. Corps of Engineers, and finally under that of Col. D. V. Woodbury, of the same corps. These regiments rendered good service as engineer troops, and at length became admirable pontoniers, as their services under fire more than once testified. We had no bridge trains whatever, for the remains of the India-rubber pontoon trains constructed for the Mexican war were of no possible use. Therefore I gave directions for the construction of trains on the model of the latest French bridge.  Capt. Duane, commanding the battalion of regular engineer troops, was charged with this duty, as well as the preparation of the other engineer trains. Capt. Duane performed this duty, as he did all that was assigned to him, in the most satisfactory manner. He on all occasions proved himself an admirable soldier and most excellent engineer. As already stated, I found it necessary to create the office of chief of staff, and selected Col. R. B. Marcy for the place. One of the greatest defects in our military system is the lack of a thoroughly instructed staff corps, from which should be furnished chief of staff of armies, army corps and divisions, adjutant-general, and aides-de-camp and recruiting officers. Perhaps the greatest difficulty that I encountered in the work of creating the Army of the Potomac arose from the scarcity of thoroughly instructed staff officers, and I must frankly state that every day I myself felt the disadvantages under which I personally labored from the want of that thorough theoretical and practical education received by the officers of the German general staff. Under our system of government, and in the circumstances which surround us, it is perhaps impossible, certainly very improbable, that this most vital point can ever be satisfactorily covered. Political and personal considerations now control so completely the appointment to places in the various branches of the staff that the chances are against their being filled by the most competent men. In fact, judging from the experience of the past few years, it is almost a certainty that incompetent men will be selected for these most important positions. Inefficiency and waste must surely result from our present system, even in times of peace; but in the event of our being thrown into collision with a well-organized European army, the results will be disastrous. Should we ever have a Secretary of War who understands his business and possesses the full support of the administration and of Congress, the work may be done. But even if commenced in the right way, the danger would be that in the course of time presidents would appoint to the corps political or personal favorites, unless the law so hedged in the corps that appointments could only be made upon the recommendation of the chief of the corps and a board of its officers after a proper test of their qualifications. I am very sure that every general officer who served in the late war will agree with me that his  labors would have been immensely lightened and the efficiency of his command very much increased if he could have had a competent staff at his disposal. In comparison with the difficulties of the work that fell to my lot the task of a general officer of the German army seems mere child's play. None of the officers at my disposal had ever seen large armies or the operations of war on a grand scale. Those who came from West Point had a good education, so far as the theory of war was concerned. That was a great advantage, but by no means all that was required. Those whom I selected were usually comparatively young men, and, under my direction, soon grasped the situation; but one very great obstacle arose from the incompetence of many of the permanent heads of departments, who found it very difficult to get out of the ruts in which they had been accustomed to move. To pass suddenly from the small scale on which the affairs of an army of 10,000 men in time of peace had been conducted, to that required for an army of half a million in the midst of a desperate war, was no easy task. I have dwelt somewhat at length on this subject in order to accentuate the difficulties of the position, and to show that the time consumed in organizing the Army of the Potomac was far from unreasonable. During the war many improvements were made in the details of the administration of the staff corps; but unfortunately no change whatever has been made in the organization of the various departments, and their only gain by the war is in the personal experience of the officers who served therein. When they have passed away there will be little or no trace left of the experience of the war. Our own experience, and that of other armies, agree in determining the necessity for an efficient and able staff. To obtain this our staff establishment should be based on correct principles, and extended to be adequate to the necessities of the service, and should include a system of staff and line education. Moreover, the officers of the staff should be required occasionally to serve with troops as officers of the line, and when the turn of each comes for promotion it should be determined not only whether he is fit for promotion, but whether he is fit to remain in the corps.  [The following memorandum by Gen. McClellan was found lying among his manuscript at this point:] General Staff Corps.--Abolish the adjutant-general and inspector-general's departments, and merge their functions in those of the general staff corps. Make the chief of the general staff a maior-general, and let the corps be composed somewhat as follows, viz:
|One brigadier-general, to perform the present duties of adjutant-general.
|One brigadier-general, to perform the present duties of inspector-general, etc.
|One colonel, assistant to the chief.
|One colonel, in charge of the department of military inspection (maps), statistics, etc.
|Two colonels, inspection duty.
|Two colonels, assistant adjutant-generals.
|Two colonels, aides-de-camp.
|One lieutenant-colonel, assistant to chief.
|One lieutenant-colonel, military statistics.
|Two lieutenant-colonels, inspection duty.
|Four lieutenant-colonels, assistant adjutant-generals.
|Three lieutenant-colonels, aides-de-camp.
|Four majors, inspection duty.
|Eight majors, assistant adjutant-generals.
|One major, statistics.
|Six majors, aides-de-camp.
|Four captains, assistant to chief.
|Four captains, military statistics.
|Eight captains, military inspection.
|Eight captains, assistant adjutant-generals.
|Six aides, general duty.