In 1919 ROTC, which had been created by the National Defense Act of 1916, began full operations on campus. All able-bodied males were required to take at least basic military training in ROTC. Originally, ROTC enrollment and training was branch specific. For example, the 1923 enrollment was 830 in Cavalry, 738 in Infantry, 236 in Air Service, 208 in Engineers, and 194 in Signal Corps. Cadets trained on campus with cannons, tanks, horses, pontoon bridges, and airplanes. Branch training in ROTC was discontinued in the mid-1960s. ROTC enrollment reached a peak of 4,772 Cadets in 1942. The University of Illinois established Naval ROTC in 1945 and Air Force ROTC in 1949. This made it one of the few Universities in the Nation with tri-service ROTC, which still holds true today.