Empirical evidence unambiguously asserts that a college education provides robust benefits to both individuals and societies. However, disparities in college enrollment and completion persist and limit opportunities for marginalized students to enjoy the advantages a college education affords, impeding progress toward equitable outcomes for all. The three chapters in this dissertation employ quantitative methods to evaluate policies and programs that aim to improve college access and success for marginalized students. The first chapter evaluates efforts to increase college access for rural students and revitalize rural economies. Results suggest a strong positive effect of branch campus openings on local economic activity. The second chapter estimates the differential impact of changes to the federal student loan policy on Historically Black Colleges and Universities (HBCUs) relative to other institutions. Results suggest that HBCUs are more responsive to these policy changes and experienced a disproportionately negative effect on enrollment when access to loans was restricted. The third chapter estimates the impact of a virtual college coaching intervention designed to help low-income, first-generation, and racial/ethnic minority students persist to degree completion. Results suggest that coaching has a positive effect on persistence to the second year, but that effect is not sustained beyond the intervention period. Together, these chapters provide evidence that informs efforts to unlock opportunity for all students and advance equity in college access and completion. [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.]