Although military issues are not often included in accounts of American society in the 1920s and 1930s, this chapter shows how they influenced young Americans’ access to education by examining debates surrounding mandatory military training that male students in certain secondary schools and colleges that were part of the Reserve Officers’ Training Corps (ROTC) program had to undergo. These debates illuminate the tensions that existed and grew between access to education and national security throughout these years, as well as the strengthening of the relationship between educational institutions and the military. The ultimate defeat of ROTC’s opponents by the end of the 1930s demonstrates that American society had come to accept the teaching of military subjects in civilian educational institutions.