Following the lead of Theda Skocpol, Jacob Hacker and other neo-institutionalists, this dissertation draws attention to the private and voluntary components of America's mixed systems of social insurance and health care provision. What distinguishes my approach is a closer view of institutional politics and policies, as well as an emphasis on their reciprocal connections with the larger political process. Drawing on the extensive administrative archives of the nation's oldest medical center, Columbia-Presbyterian Medical Center in New York, I reconstruct and analyze some of the formative moments of the American health care system. Two broad conclusions concerning American health care politics emerge from my analysis. First, academic medical centers, as well as private health care institutions more generally, make policies and shape health care politics. Thus, private institutions are policy-makers, in a very real sense. Second, private institutions of health care provision have participated in the making of health care policy not as monolithic, autonomous institutions but as internally contested and externally invested organizations. On the basis of my research, I propose a new theoretical framework which brings into view the organizational and social dimensions of health care politics that have been previously overlooked. The framework builds on two theoretical approaches - the neo-Durkheimian theory of micro-classes and the theory of intersectionality - to reveal a coherent set of political subjects and structures involved in health care politics. Central to this framework is a concept of 'institutional class positions,' which links the mechanisms of bureaucratic power and occupational control with the effects of gendered and racialized systems of inequality to produce an integrated, dynamic understanding of institutional processes. I show that the organizational and social structures which shape these positions have far-reaching political effects, indicating the limits and possibilities of health care reform in the predominantly private framework of health care provision.