ARMOR-CAVALRY: Part 1; Regular Army and Army Reserve/Cavalry between the World Wars

by Mary Lee Stubbs and Stanley Russell Connor

• Between the wars the cavalry was slow in adopting mechanization. A factor bearing on the reluctance was that tanks were legally the responsibility of infantry. Although use of the tank by cavalry, as a supplement to achieve the utmost in mobility, had some support, cavalry clung to the horse as being indispensable to its type missions. Immediately after the war, the tank's slow speed was no minor consideration in the cavalry's reluctance to accept it. A few light mechanized vehicles were being used in cavalry units by the late 1920's, however, and the mechanized cavalry regiment, equipped with combat cars, came into being in the early 1930's. Actually the combat cars were modified infantry tanks, but were called combat cars to distinguish them from the tanks of infantry.

• Staunch cavalrymen contended that the stalemate on the Western Front in World War I was the exception, not the rule, and that cavalry, with its essential characteristics of mobility and firepower, would have an important place in future warfare. They believed, however, that the very distant reconnaissance missions performed by cavalry in its strategical role would, for the most part, be taken over by the airplane.

• After World War I, the AEF Cavalry Board concluded that "the role of cavalry, in general, has changed but little when considering war of movement." Although small units up to squadron size would "still have opportunities for mounted action …," the AEF Board continued, "the mounted combat of large bodies of cavalry is probably a thing of the past." The board's recommendation that cavalry units not be assigned as organic elements of infantry divisions, but that they be attached for operations, as needed, was accepted.

• The Office of the Chief of Cavalry was established by the 1920 National Defense Act, and Maj. Gen. Willard A. Holbrook was appointed as the first chief. The total personnel authorization for cavalry was set at 950 officers and 20,000 enlisted men; its actual strength on 30 June 1920 was 965 officers and 15,812 men. In numbers of units, cavalry was little affected by the immediate reduction in the Regular Army at the war's end, since the mounted arm already had been fixed at 17 regiments.

• In addition to the established regiments, squadrons, and troops, the larger units of cavalry divisions and brigades were provided by the 1920 act. Two cavalry divisions, the 1st and the 2d, were added to the Regular Army, the 1st being active and the 2d inactive. Each division contained two cavalry brigades, and each brigade had two regiments, a machine gun squadron, and a headquarters troop. Other divisional elements were a horse artillery battalion with 75-mm. guns, a mounted engineer battalion, an ambulance company, the division trains, and the special troops (headquarters, signal, ordnance, and veterinary) .

• The reorganization of the cavalry under the 1920 act took place in 1921. By then, lack of funds and reduced personnel authorization for the Army had cut the mounted arm to less than half of its former strength. Except for a regiment of Philippine Scouts- the 26th Cavalry, which was organized in 1922- the number of cavalry regiments was pared from seventeen to fourteen by inactivation of the 15th, 16th, and 17th. The remaining regiments were reconstructed to consist of a headquarters, a headquarters troop, a service troop (redesignated from the former supply troop), and only six lettered troops. The troops, designated as A through F, were grouped into two squadrons of three troops each. The regimental machine gun troop was eliminated, since its pack animals were believed to reduce the regiment's mobility. Machine gun troops and other surplus elements of the regiment were either redesignated into newly organized units or disbanded. Among those newly organized were machine gun squadrons, separate machine gun troops, training center squadrons, and the headquarters troops of two cavalry divisions and four cavalry brigades. All in all, the mounted arm lost three whole regiments and ninety-eight troops, some of the troops having been in continuous existence for almost a hundred years. By mid-1923 the assigned strength of cavalry had dropped to 721 officers and 8,887 men, which is approximately where it stood until the late 1930's.

• The unit organizations effected in 1921 lasted seven years, major changes not coming until February 1928. At that time, lettered troops of the regiments were decreased from six to four. Troops A and B of each regiment formed the 1st Squadron, and E and F formed the 2d Squadron. Also, separate machine gun squadrons and troops were eliminated, and the machine gun troop was returned to the regiment.

• This new regimental organization was designed to reduce overhead, increase firepower, and retain mobility. It provided for easy expansion to war strength and retained for the regiment, if required to take the field at peacetime strength, the capability of delivering powerful and flexible firepower. This firepower had been increased not only by the return of the machine gun troop to the regiment, but by doubling the machine guns in that troop from four to eight. Reduction in wagons and pack animals in the new regiment was offset by the addition of three 1½-ton trucks and three stripped, modified automobiles, called light crosscountry cars.

• Many famous old cavalry units were dangerously near being lost to the Army because of these organizational changes. But the policy of retaining surplus units on the rolls of the Army in an inactive status was established, permitting units to be preserved for future use rather than being disbanded or redesignated. As a result, most former cavalry troops have been restored to their original regiments.

• The strength and composition of cavalry regiments of 1928-39 were principally governed by the total strength of the Army, the number of regiments kept active, and the desire for a troop large enough to be an effective fighting unit, even at peacetime strength. For that period each regiment had an approximate average of 690 men: headquarters troop, 78; band, 28; 4 rifle troops, 119 each; and a machine gun troop, 108. Each rifle troop had a troop headquarters, 3 rifle platoons of 3 squads each, and a machine rifle platoon, also of 3 squads.

• The real beginning of the Armored Force was in 1928, twelve years before it was officially established, when Secretary of War Dwight F. Davis directed that a tank force be developed in the Army. Earlier that year he had been much impressed, as an observer of maneuvers in England, by a British Experimental Armored Force. Actually the idea was not new. A small group of dedicated officers in the cavalry and the infantry had been hard at work since World War I on theories for such a force. The continued progress in the design of armor, armament, engines, and vehicles was gradually swinging the trend toward more mechanization, and the military value of the horse declined. Proponents of mechanization and motorization pointed to advances in the motor vehicle industry and to the corresponding decrease in the use of horses and mules. Furthermore, abundant oil resources gave the United States an enviable position of independence in fuel requirements for the machines. Although the horse was not yet claimed to be obsolete, his competition was gaining rapidly, and realistic cavalrymen, sensing possible extinction, looked to at least partial substitution of the faster machines for horses in cavalry units. As late as 1938, on the other hand, the Chief of Cavalry, Maj. Gen. John K. Herr, proclaimed, "We must not be misled to our own detriment to assume that the untried machine can displace the proved and tried horse." He favored a balanced force made up of both horse and mechanized cavalry.

• Secretary Davis' 1928 directive for the development of a tank force resulted in the assembly and encampment of an experimental mechanized force at Camp Meade, Maryland, from 1 July to 20 September 1928. The combined arms team consisted of elements furnished by Infantry (including tanks), Cavalry, Field Artillery, the Air Corps, Engineer Corps, Ordnance Department, Chemical Warfare Service, and Medical Corps. An effort to continue the experiment in 1929 was defeated by insufficient funds and obsolete equipment, but the 1928 exercise did bear fruit, for the War Department Mechanization Board, appointed to study results of the experiment, recommended the permanent establishment of a mechanized force.

• The Army Chief of Staff, General Charles P. Summerall, was convinced that the tank must be included in the artillery-infantry-machine-gun team, although he had reported in 1928 that the Renault tank had "demonstrated that it was too slow to operate with Cavalry." Just before leaving office in October 1930, General Summerall directed: "Assemble that mechanized force now, station it at Fort Eustis, Virginia. Make it permanent, not temporary."

• Within a few weeks the Mechanized Force was organized at Fort Eustis, with Col. Daniel Van Voorhis commanding. Through his leadership in the early development of mechanization, Van Voorhis earned the title of "Grandfather of the Armored Force."

• When cavalrymen began to think in terms of a balanced mechanized force in 1931, they, like infantrymen, also preferred the light tank for use in the traditional role of light cavalry. For all practical purposes, therefore, the early 1930's found both the cavalry and the infantry, though internally divided over tactical doctrine, firmly committed to the light tank.

• The separate Mechanized Force at Fort Eustis was short-lived, for the War Department, under a new Army Chief of Staff, General Douglas MacArthur, decided in late 1931 to dissolve the organization. In its place, all arms and services were directed to adopt mechanization and motorization, "as far as is practicable and desirable," and were permitted to conduct research and to experiment as necessary. Cavalry was given the task of developing combat vehicles that would "enhance its power in roles of reconnaissance, counterreconnaissance, flank action, pursuit, and similar operations." One of its regiments was to be equipped exclusively with such vehicles. Infantry was to give attention to machines intended to increase its striking power against strongly held positions. Although General MacArthur further decreed that "no separate corps will be established in the vain hope that through a utilization of machines it can absorb the missions, and duplicate the capabilities of all others," increased emphasis was placed upon mechanization.

• Two years later General MacArthur set the stage for the coming complete mechanization of the cavalry, declaring, "The horse has no higher degree of mobility today than he had a thousand years ago. The time has therefore arrived when the Cavalry arm must either replace or assist the horse as a means of transportation, or else pass into the limbo of discarded military formations. But," he went on, "there is no possibility of eliminating the need for certain units capable of performing more distant missions than can be efficiently carried out by the mass of the Army. The elements assigned to these tasks will be the cavalry of the future, but manifestly the horse alone will not meet its requirements in transportation."

• The organizational structure planned for the new mechanized cavalry regiment in 1932 was similar to the horse regiment. With an authorized strength of 42 officers and 610 enlisted men, the mechanized regiment was divided into a covering squadron, a combat car squadron, a machine gun troop, and a headquarters troop. Like the horse regiment, it had four lettered troops but was equipped with combat vehicles instead of horses. Its covering squadron was divided into an armored car troop and a scout troop, while the combat car squadron had two combat car troops. The mechanized regiment had thirty-five combat cars (light, fast tanks), which were about equally divided among the troops of the combat car squadron and the scout troop of the covering squadron.

• Great mobility, armor protection, and firepower were the distinctive characteristics of mechanized cavalry. Its principal role was "in employment on distant missions covering a wide area," but it was not expected to hold objectives for prolonged periods without support of artillery and infantry or horse cavalry.

• The cavalry division, in which other arms were combined with cavalry, also underwent organizational changes designed to take advantage of the speed and striking power of modern machines. In the new division three types of units were added- an armored car troop, a tank company, and an air observation squadron. The division retained its 2 horse brigades and had an aggregate war strength of 465 officers and 8,840 men.

• Cavalry selected Fort Knox, Kentucky, as its site to develop and test combat vehicles; personnel and equipment from the Fort Eustis force formed the nucleus of the command. In early 1933 the 1st Cavalry arrived from Marfa, Texas, and the process of replacing horses with machines in the regiment began. Thus did the first American mechanized cavalry organization come into being. During the next four years other units, including a battalion of field artillery, a quartermaster company, and another cavalry regiment, the 13th, were moved to Fort Knox and mechanized. The War Department in 1938 modified its 1931 directive for all arms and services to adopt mechanization and motorization. Thereafter, development of mechanization was to be accomplished by two of the combat arms only- the cavalry and the infantry.

• In early 1938 the two cavalry regiments and other Fort Knox units were used to reorganize the 7th Cavalry Brigade, with Brig. Gen. Daniel Van Voorhis in command. Later that year he was succeeded by Col. Adna R. Chaffee. Formerly second-in-command of the Mechanized Force at Fort Eustis, Colonel Chaffee was already a well-known pioneer in, and strong advocate of, mechanization. Recognized as the "Father of the Armored Force," he dedicated his career to the development of armor not only through his service at Fort Knox but also on the War Department General Staff.

• The shockingly quick success of the German blitzkrieg into Poland in September 1939 profoundly affected military tactics and doctrine around the world, but perhaps nowhere was the impact greater than upon the cavalry of the U.S. Army. Tank enthusiasts at Fort Knox now began to advocate publicly what they had been considering privately- the formation of true armored divisions, including tanks, motorized infantry, and other arms and services.

• Although mechanized cavalrymen had no initial success in their attempts to form armored divisions, a motorized infantry regiment, the 6th, was added to the Fort Knox brigade for the 1940 Louisiana maneuvers. An improvised armored division, formed with the 7th Cavalry Brigade (Mechanized) and the Provisional Tank Brigade from Fort Benning, proved successful- the mechanized troops, in effect, dominated the maneuvers.

• Besides the 7th Cavalry Brigade, composed of the 1st and 13th Cavalry (Mechanized), the Regular Army cavalry in 1940 had 12 regiments, 2 of which were horse-mechanized, and the 26th Cavalry of the Philippine Scouts (Regular Army officers with Filipino enlisted men). In addition, 18 cavalry regiments were in the National Guard and 24 in the Organized Reserves.