"Unescorted Guests" provides a richly detailed portrait of a fundamental change at one US institution: Yale University's 1969 transition from an all-men's to a coed college. This study disputes several dominant narratives about the 1970s youth and women's movements, and deepens our understanding of three core issues in higher education research: access, the experiences of previously excluded students, and change towards greater equity. I contest the myth of alumni as foes to coeducation, and show that the greatest opposition to equity for women came instead from Yale's president and trustees. I document how women students, absent as powerful figures in youth movement history, played a key role in pushing change at Yale. I show how women administrators, missing from standard social movement depictions of change, created power to advance equity despite efforts to undermine them. I chronicle the key role played by the federal government and the broader women's movement in advancing change for women at Yale, and conversely the ways that Yale used its power to slow progress for women. I challenge, through multiple sources of evidence, the idea that access alone brought equity for women. "Unescorted Guests" also provides for the first time a comparison of the experiences and activism of black and white women students in a predominantly white college, a description of the sexual harassment and assault experienced by women at an elite college in the early 1970s, a joint portrait of women administrators and students at a newly coeducational institution, and 1970s student outcome data broken out by race, class, and gender. Lastly, this study contributes to the literature through using archival evidence, interviews, and contemporary press absent in earlier studies, most notably those providing the voices of women; showing how theory can strengthen the trustworthiness of historical narrative; and probing the practical implications of this historical study. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]