Texas A&M University is a senior military college that offers participation in military Reserve Officers Training Corps (ROTC) programs. The university has a standing cadet corps, known as the Texas A&M University Corps of Cadets, which is a student-led, military-style organization. The Corps of Cadets is composed of three Air Force Groups, three Army Battalions, and three Navy/Marine units, representing all military branches. The Corps of Cadets is the oldest student organization on campus, established with the university in 1876. Students who elect to join the Corps must participate in mandatory ROTC courses and training for the first three semesters, but they are optional after that. Approximately 45 percent of the members of the Cadet Corps continue with the ROTC curriculum, contract with the military, and receive commissions as officers in the United States armed forces upon graduation.