This qualitative case study examines connections between student writing and student success, specifically among first-generation college students, a growing student population who are less likely to graduate college than their multigenerational peers. First-generation college students are more likely to come from working-class, low-income backgrounds, identify as racial or ethnic minorities, live at home and/or have significant family and work responsibilities (Bond, 2019; Engle & Tinto, 2008). Due to the confluence of barriers many face, first-generation college students exhibit higher attrition rates, contributing to persisting inequities in higher education. Leveraging Rendon's (1994) validation theory, this study explored how first-generation college students experienced validation in a first-year writing course, and how those experiences influenced their ability to see themselves as creators of knowledge, valuable members of the university learning community, and capable of success. Specifically, the study identified moments of academic and interpersonal validation in a first-year writing course to better understand how validation may help support first-generation college students' success. Through students' reflective writing assignments, interviews with students and instructors, classroom observations, and analysis of pedagogical and curricular artifacts, the study findings indicate that students do experience academic and interpersonal validation in first-year writing and that the validation contributes to their ability to view themselves as capable of success in college. Based on the results, the study offers recommendations for improving pedagogy and practice, and further research to cultivate more equitable success. [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.]