The Square Division—Basic Fighting Unit of the AEF

President Wilson and General Pershing Review the  Assembled 26th Yankee Division, Christmas Day 1918

The U.S. Army first used divisions during the Revolutionary War as administrative commands and only much later did they evolve into semipermanent tactical organizations. Divisions used during the War of 1812 tended to be ad hoc formations. In the mid–nineteenth century the division began to mature as an organizational concept and significant operational and strategic instrument. Being greatly influenced by the Napoleonic hallmark of dividing armies into divisions—the first modern independent field maneuver units—General Winfield Scott first organized American troops into divisions for the purpose of flanking operations during the Mexican War in the 1840s.

Divisions were later used prominently in the American Civil War, but peacetime divisions would not come into existence until early in the next century. The U.S. Army then followed the examples of the large European armies, which had adopted permanent division designs by the 1890s.

Officers of the 34th "Red Bull" Division

The first U.S. Army division of the 20th century was conceived not necessarily with combat power in mind, but primarily as an administrative formation used to aid mobilization. Its roots lie in an effort to improve training procedures and the speed of assembly. America’s experience in its war with Spain in 1898 spurred a rethinking among the Army’s bolder leaders of its organization for fighting.

Secretary of War Henry Stimson and Army Chief of Staff General Leonard Wood also wished to eliminate the many small posts inherited from the constabulary and Indian fighting days and reorganize the Army into larger garrisons. At the very least, Wood and Stimson believed that they should form temporary troop concentrations on paper that would aid mobilization purposes. The so-called “Maneuver Division” was formed at San Antonio, Texas, in March 1911. This grouping gave officers experience handling large bodies of men and permitted testing and experimentation with new Signal Corps equipment, such as telegraph and wireless telegraph sets (radios) and airplanes. The shortcomings of the resulting undermanned and unprepared Maneuver Division later gave Army leaders the ammunition to call for an improved organization of the Army as a whole. Stimson subsequently called on the U.S. Army War College to plan for the tactical reorganization of the Army into a permanent, division - based organization.

In early 1913, Stimson persuaded the Army’s general officers of the merits of the divisional plan, and the reorganization of the Army into four divisions soon followed. These divisions consisted of three infantry brigades, a cavalry regiment, an engineer battalion, a signal company, and four field hospitals. The wisdom of the new plan soon became evident as the Mexican Revolution threatened to spill over the Rio Grande. What once required scores of orders now required only one, and with that the 2nd Division commanded by Brigadier General Frederick Funston at Texas City and Galveston was mobilized.

The Army’s first permanent division was organized on 8 June 1917, as the 1st Expeditionary Division. During the mobilization for American involvement in World War I, U.S. Army leaders noted the Allies’ experiences and reorganized the division design with a new approach to two traditional Army hallmarks, mobility and firepower.

The Americans did not want to get bogged down as the French and British had and designed and trained their forces to break the stalemates prevalent on the Western Front. Maintaining the momentum of attacks through sustained firepower was placed at a premium. While the Americans retained an open warfare style that had been abandoned by their allies, mobility was not a key consideration for organizing.

In Maneuver and Firepower, Wilson states that Chief of Staff Major General Hugh L. Scott originally leaned toward a smaller square division of about 13,000 men to facilitate mobility and the exchange of men on the line. Following British and French recommendations, a subsequent study conducted at the War College led to a division of nearly 19,000 men (including more than 10,000 infantrymen) that resembled the French square division, enlarging the regiments by reducing their number from nine to four, and slashing the amount of cavalry significantly. The Allies felt that cavalry had little utility in trench warfare, while horses and fodder would take up too much valuable shipping space. General John J. Pershing and Colonel Chauncey Baker later altered the underlying assumptions of division organization: instead of facilitating the movement in and out of the trenches, the division should be organized and sized to fight prolonged battles. They felt that the Allies would have increased the size of their divisions had they the luxury of abundant manpower. An infantry company was restored to each battalion, bringing the total to four in each, while augmentations to machine gun assets brought the U.S. Army square division to more than 27,000 men.

Single Infantry Company of the 36th Texas-Oklahoma Division

Pershing was also an unabashed fan of the American soldier, believing that with innate American initiative and more divisional combat power, he could succeed where the Allies had failed. In his book Fast Tanks and Heavy Bombers (Ithaca, NY: Cornell University, 1998), David E. Johnson notes that Pershing felt American officers and infantrymen were superior to those of the tired Allies. Johnson adds that, unlike the Allies, the Americans still believed in the inherent power of the infantry charge with fixed bayonet, and they were successful with this “open warfare” doctrine—contrary to the British, French, and German experiences—only because of prevailing conditions on the Western Front that were conducive to such an approach. Meanwhile, infantry-artillery coordination was not yet smooth enough to engender effective maneuver: communications between infantry and artillery were still rudimentary, and artillery itself was not yet mobile enough to keep up with infantry advances.

Traditional American tactical inclinations toward mobility and open warfare were made moot because of certain technological aspects of the battlefield in World War I, notably the machine gun and the limitations on effective artillery due to poor self-mobility and archaic methods of communication. The Army may have had a predilection for a more mobile style of warfare, but without effective artillery fire to support maneuver, the infantry was constrained to move slowly

The pre-World War I triangular design was deemed insufficient, lacking enough flexibility, control, and sustainable combat power. De-emphasizing mobility and maneuver, the division was to be bulked up and reorganized to fight prolonged battles in sustained frontal attacks.11 While not totally abandoning mobility, this cornerstone of U.S. Army warfare was sacrificed somewhat in the interest of firepower needed to penetrate German defenses and exploit breakthroughs. The commander of the American Expeditionary Force, General John J. Pershing, fixed the division at 979 officers, 27,082 men (about 40,000 all told, including support personnel).

Pershing created this division—which was more than twice the size of its European counterpart—to “achieve a capacity for sustained battle which would ensure that American divisions would not falter short of their objectives as British and French divisions so often had done.” A division with fewer but larger regiments would facilitate a more reasonable span of control and battle momentum. Similar to—albeit larger than—early European “square” designs, the American square division consisted of two infantry brigades of two regiments each, one field artillery brigade (two 75mm regiments, one 155mm regiment), an engineer regiment, a machine gun battalion, a signal battalion, and division supply, and sanitary trains. Each infantry regiment had a strength of 112 officers and 3,720 men formed into three battalions and one machine-gun company. Each battalion consisted of four companies of six officers and 250 men each.

First Artillery Brigade of the 1st Division, 1919

Although it possessed tremendous firepower, this division could not fully capitalize on its assets and was also hindered by insufficient numbers of combat service support troops and equipment. Coordination between infantry and artillery was poor, hampered by unreliable communications equipment and the inability to keep track of the movement of infantry units in the offensive. Successful offensives were thereby slowed tremendously. A shortage of personnel and equipment specifically reserved for general logistical requirements, medical evacuation, and transporting rations and the dead further slowed the advance. In short, the square division lacked coordination and was unwieldy and difficult to support logistically.

The interwar period would prove to be important for incorporating lessons learned from World War I into the division design. Chief among them was the fact that greater coordination among the combat arms and support was required to enhance combat effectiveness. Advances in weapons, communications, and transportation technology were needed to improve the division’s lethality, while properly integrating the advances into Army formations and operations was equally important.

Immediately after the war, many veteran officers recommended that the Army retain the square divisional structure. General Pershing objected, believing that these evaluations came too soon after the conflict and were heavily influenced by the special circumstances of the Western Front. He favored a division that was much more mobile and flexible and proposed a design possessing a single infantry brigade of three infantry regiments, an artillery regiment, a cavalry squadron, and combat support and combat service units. Time and distance factors were paramount: “The division should be small enough to permit its being deployed from . . . a single road in a few hours and, when moving by rail, to permit all of its elements to be assembled on a single railroad line within twenty-four hours; this means that the division must not exceed 20,000 as a maximum.”

The debate over the divisional structure was framed by the assumption that North America would be the theater in which it would most likely be deployed. The static battlefield, characteristic of World War I in Western Europe, was viewed as a thing of the past as “technological advances in artillery, machine guns, and aviation made obsolete stabilized and highly organized defensive lines whose flanks rested on impassable obstacles, such as those encountered on the Western Front.”

The Decks of the Returning USS Agamemnon Holding
Only a Portion of the 26th Yankee Division

However, despite Pershing’s preference for a much smaller and flexible division of three regiments, two prominent redesign efforts, the Superior Board (1919) and Lassiter Committee (1920), recommended square designs. In answering the call to increase mobility, the division was cut in size by reducing from four to three both the number of platoons in infantry companies and the number of companies in battalions; 155mm howitzers and some support troops were also eliminated. It is interesting to note that the Lassiter Committee wished to retain the brigade-based square division in part because a triangular design would have eliminated the brigade command billets filled by brigadier generals. The reduced square division was tentatively approved by Army Chief of Staff General Peyton March in August 1920 at 19,385 men and grew to 19,997 men a year later. Pershing, who was to become chief of staff soon after, may have ultimately acceded to a smaller square design because he wished to avoid embarrassment: many of his own officers had recommended the square design while serving on the Superior Board. At the same time, following much criticism for the bloated and unwieldy 1917 design, the postwar cavalry division was radically reduced from approximately 18,000 men to 7,463.

Sources: Excerpted from Chapters 2 & 3 of Evolution and Endurance: The U.S. Army Division in the Twentieth Century, Richard W. Kedzior at the Rand Corporation Website.