History of The United States Army - Twentieth Century

Twentieth Century

In 1910, the U.S. Signal Corps acquired and flew the Army's first aircraft, the Wright Type A biplane.

The Maneuver Division was formed in San Antonio, Texas, in March 1911, to undertake offensive operations against Mexico during the Mexican Revolution. This was the United States' first attempt at modernizing the division concept. Major General Leonard Wood, then Army Chief of Staff, mobilized the division primarily to demonstrate to Congress that the United States was not adequately prepared for modern warfare. The division was disbanded on 7 August 1911.

Because of the mobilization difficulties experienced with the Maneuver Division, on 15 February 1913 a standing organization of a "regular army organized in divisions and cavalry brigades ready for immediate use as an expeditionary force or for other purposes..." and "an army of national citizen soldiers organized in peace in complete divisions and prepared to reenforce the Regular Army in time of war" was organized by Secretary of War Henry L. Stimson and known as the "Stimson Plan." The continental United States was divided into four geographic departments (Eastern, Central, Western, and Southern) and a regular army division assigned to each, and 12 geographic districts, each with a national guard infantry division assigned. 32 of the 48 state governors committed their national guards to support of the plan. There were also three artillery commands: the Northern Atlantic Coast Artillery District, the Southern Atlantic Coast Artillery District, and the Pacific Coast Artillery Discrict.

In 1914 and 1916, U.S. troops were sent into Mexico during the Mexican Revolution. The Pancho Villa Expedition under Brigadier General John J. Pershing attempted to capture Pancho Villa, a Mexican who had mounted attacks on U.S. border towns. The skirmishes on the border later became known as the Border War (1910–1919).