This paper charts the transformation of the employment relationship in different industries during the second quarter of this century and is based on a representative sampling of U.S. business organizations. The first section documents changes in the control systems that prevailed in U.S. industries between the Depression and the end of World War II. The descriptive analyses generally corroborate portraits that have recently been provided by neo-Marxists of how and where technical and bureaucratic controls evolved. The second section sketches and explanation for the rapid diffusion of bureaucratic controls that apparently occurred between 1939 and 1946. It examines the role of three key constituencies in shaping modern system of work force control: labor unions, personnel professionals, and the state. In particular, the analyses underscore the large role of government intervention in manpower activities during World War II in bureaucratizing employment. This effect of the state blurs the distinction between "efficiency" and "control" explanations of bureaucratic controls and internal labor markets, calling attention to institutional sources of change in organizations' employment structures. The concluding section highlights the implications of the findings for efforts to understand the employment relationship.