The training of U.S. physicians in aviation medicine closely followed the development of reliable airplanes. This training has matured as aviation and space travel have become more routine over the past several decades. In the U.S., this training began in support of military pilots who were flying increasingly complex aircraft in the early part of the 20th century. As individuals reached into the stratosphere, low Earth orbit, and eventually to the Moon, physicians were trained not only through military efforts but in academic settings as well. This paper provides an historical summary of how physician training in aerospace medicine developed in the U.S., citing both the development of the military activities and, more importantly, the perspectives of the academic programs. This history is important as we move forward in the development of commercial space travel and the needs that such a business model will be required to meet.