In 1891, the University of Arizona was allowed to open its doors under the provisions of the 1862 Morrill Act. These provisions were regulated by the Legislative Assembly of the Territory of Arizona and required that military training be taught at the university. The first University Catalogue provided for a Professor of Military Science and Tactics; however, no classes were conducted.

In March of 1896, the faculty resolved that a Military Science and Tactics course be conducted for all male students. During this first year, the Cadet Battalion was intended to be affiliated with the Arizona Territorial National Guard. This permitted the territorial Governor to commission those cadets who desired and were worthy of a National Guard Commission.

In 1920, the establishment of Cavalry instruction transformed the program into a close relationship with the University administrators, students, and intercollegiate sports. Cavalry instruction provided horses for the popular college sport of polo. Cavalry instruction and polo proved extremely popular with the Arizona community and the University.

In the four years following World War II's outbreak, 11,000 military men received training at the University of Arizona in four different programs. The University reported in 1945, over 10,000 men graduated from the Naval Training School, 591 from the Naval Aviation School, and 283 from the Army Specialized Training Program. Along with 331 from the Civil Aeronautics Authority's two programs.