This study examines how and why faculty senates were created in American research universities. Senates were created by faculty in reaction to conditions on campus, such as faculty dissatisfaction with their role in institutional governance, or were created by presidents as a means to proactively modernize the functions of the university. In some cases, the conditions that lead to the creation of a senate were dramatic crises that immediately brought to light the limitations of the campus governance system. A major cause for the creation of senates was the growth of the faculty of the university, which created a need for a representative body to replace meetings of the faculty as a whole. At the time of instituting senates, universities were also making improvements in the quality of the faculty and becoming increasingly focused on research. This study employed theories of political power (agenda setting) to demonstrate how the creation of a senate took place. The creation of a senate was advocated by an entrepreneur who took advantage of existing conditions during a window of opportunity to advocate for a change in the role for faculty in university governance. The creation of faculty senates at 151 universities was investigated and historical case studies were conducted at six institutions: the University of Utah, the Pennsylvania State University, the University of Virginia, the University of Pittsburgh, the University of Pennsylvania, and Carnegie Mellon University. The study is divided by era, examining senates created in the university building period, during World War II and the post-war period, and during the 1960s and 70s. Universities that have not created a university-wide senate are also discussed. Ultimately, senates were created proactively to improve the campus organization or reactively, in response to conditions or crises that drew attention to inadequacies in the governance structure.