This study narrates the origin of radar at the Naval Research Laboratory. Radar should be seen as the product not simply of one man or even a group of men but rather as the result of individuals working within the structure of a mission-oriented research-and-development facility. To comprehend how radar was developed, when it was developed, and why, one must follow not just the evolution of technical progress but also the administrative and political decisions that shaped it. One must understand how the talents and motivations of the people who created this new device were related to the particular institutional situation and historical context in which they labored. The account is the story of a modern research-and-development laboratory in action. It discusses one major accomplishment of one institution. But it is also written to contribute to a broader understanding of the history of research and development laboratories in general and of the influence they have had on the course of modern American history. The work of the Naval Research Laboratory on radar is a significant episode in that story.