Iowa had organized the 1st Cavalry Squadron in 1915, a unit with four troops (companies) and which had seen service on the Mexican frontier during the pursuit of Pancho Villa. During World War I, the squadron was split up; Troop A became the division headquarters troop for the 34th Division, Troop B was reorganized as part of the 125th Machine Gun Battalion, 34th Division, Troop C was reorganized as part of the 133rd Infantry Regiment, 34th Division, Troop D was reorganized as part of the 109th Ammunition Train, 34th Division, and the band was reorganized as part of the 301st Cavalry Regiment. The 34th Division shipped to France in late 1918, but did not see any combat, and the 301st Cavalry Regiment was converted to field artillery units in the summer of 1918, but none of these units shipped overseas before the end of the war.