This paper explores the rise of the National Institutes of Health after World War II from the perspective of intramural scientists working at the NIH's main campus in Bethesda. Several postwar social circumstances—the local research tradition, the wartime experience of civilian scientists, the doctor draft, and anti-nepotism rules in academia—affected the recruitment of research-oriented scientists into the NIH. These historically contingent factors were no less important than the larger political, legislative context for the development of the NIH intramural program as a prominent research institution.