The project will provide a new examination of postwar American science by focusing on the national laboratory system. The national labs continue to occupy a central place in the American scientific landscape. This project will examine the path they have traveled and how it was chosen. Specifically it will focus on the history of the national laboratory system during the tenure of the Atomic Energy Commission, in order to shed light on the implications of systemicity and the negotiation of research programs among the labs. The project will integrate two approaches. An overview will place the national laboratory system in its historical context, describe its evolution, and address general issues about the system. Within this overview, three case studies will exemplify the workings of the system for different aspects and different periods. In particular, the case studies will shed light on the implications of systemicity and the negotiation of research programs among the labs.