This chapter is based on the Thirteenth Reynolds Lecture, which, in turn, is based not on archival research but on a reconstruction of duties in the Office of the Surgeon General of the Army during World War II. The dominance of specialty and subspecialty medicine that came to characterize US medicine in the post-World War II era was the direct consequence of the emphasis that the Army Medical Department placed on specialist care during World War II. Looking back with the advantage of more than forty years of perspective, these are the lessons learned. While there is no question that the Army Medical Department had most of the resources it needed in World War II, resources alone were not enough. They needed to be part of a system in which patients were matched with physicians and with appropriate medical centers where the specialists were effectively supported.