This dissertation examines the trajectory of research programs on women and gender in American universities between 1970 and 2010. The dissertation melds perspectives in the sociology of science with organizational analyses of the development of academic disciplines. The analysis forwards a new understanding of how local conditions in research settings influence the trajectory of interdisciplinary development. Women's and gender studies is an interdisciplinary field that originated in connection with second wave feminism and the accompanying view that previous scholarship had omitted women when drawing conclusions about the population. In its developmental trajectory women's studies underwent a process of intellectual and institutional diversification. Women's studies programs began with uniform intellectual goals: to address the lack of scholarship on women and to analyze problems related to sex stratification. As programs spread, scholars across institutions redefined their research interests, incorporating topics that transcended the study of women, such as masculinities and sexual identity. The diversification of research agendas in gender studies across universities was uneven, a result of shifting resources and relationships within programs and the pliable quality of objects of analysis like "women" and "gender," which are used in increasingly diverse ways. I introduce the concepts of knowledge "ecologies" and "supple objects" to explain the diversification of women's and gender studies programs and departments, arguing that the local conditions within departments bore an intimate relationship with the way scholars defined and use core categories of knowledge over time, and, consequently, with the way departments set priorities around studying women and gender. The finding that programs began with homogenous content and diversified only later in their development is distinct from "new institutional" models that see the departments that form a discipline as becoming more structurally similar over time, as well as models that see departments as bearing the distinct imprints of their founding conditions over time. Data are archival records from women's and gender studies departments and programs, semi-structured interviews with professors, data on employment and career trajectories of scholars with appointments in programs, and content analysis of research output. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]