similar to that mandated in 1914. Internal changes dealt with firepower, another consequence of observing the pattern of the European war. Infantry regiments gained additional riflemen, and the provisional headquarters, supply, and machine gun companies were made permanent. The field artillery brigade also gained considerable firepower, with one regiment of 3.8-inch howitzers and two regiments of 3-inch guns replacing the two regiments authorized in 1914. A two-battalion engineer regiment replaced the battalion, the signal battalion grew in size, and an aero squadron equipped with twelve aircraft joined the division for reconnaissance and observation. Enlarged ammunition, supply, engineer, and sanitary trains supported the arms, and the tables provided for the trains to be either motorized or horse-drawn. The tables also called for a headquarters troop for the division and headquarters detachments for infantry and artillery brigades. These units were to furnish mess, transport, and administrative support for the division to operate on a more complex battlefield. The redesigned division for war numbered 28,256 officers and enlisted men when the trains were authorized wagons or 28,334 when they were authorized motorized equipment (Chart 1).[1]
The staff, in rationalizing the division, divided the road space it would use between combat and support elements. Combat elements used fourteen miles, while the support elements, depending on whether the trains were motorized or horse-drawn, used five to six miles. Although it required about twenty miles in march formation, a 25 percent increase in road space over the 1914 organization, the division was still thought to be able to move to battle on a single road.[2]
The new tables dramatically changed the structure of the cavalry division for war. Cavalry brigades reverted to three regiments each, and the nine cavalry regiments acquired permanent headquarters, supply, and machine gun troops. As in the infantry division, the cavalry division fielded an aero squadron. The tables also introduced a divisional engineer train and enlarged the ammunition, supply, and sanitary trains. The division headquarters and headquarters troop and brigade headquarters and headquarters detachments rounded out the unit. Given these changes, the size of the division rose from 10,161 to 18,164 when the trains were equipped with wagons and 18,176 when they were equipped with motorized vehicles (Chart 2), and it occupied approximately nineteen miles of road space on the march.[3]
To achieve the mobilization force that the Statement of Proper Military Policy proposed—six cavalry brigades, two cavalry divisions, and twenty infantry divisions—the Army needed more troops. In 1916 Congress increased the number of Regular Army regiments to 118 (7 engineer, 21 field artillery, 25 cavalry, and 65 infantry) and increased the size of the National Guard, 800 men for each senator and representative, to be raised over the next five years. Several developments, however, interfered with implementation of the Regular Army portion of the act, especially activities along the Mexican border, a reduction in the General Staff that prevented appropriate planning, and the nation's plunge into the European war.[4]
