The first-year writing (FYW) course is located at a crucial moment in a student's educational pursuits: it is one of the few required courses that nearly all students must take, and success in this course is often an early indicator of whether a student is likely to graduate. This dissertation examines how writing assessment and FYW have been used as a gatekeeper to higher education, keeping historically marginalized or nontraditional students out of four-year institutions. Open-access institutions such as community colleges are one answer to these gatekeepers; however, community college students are, on average, most vulnerable to gatekeeping pedagogies and policies. In order for our FYW courses to be fully equitable, therefore, we must lean into a gateway pedagogy -- a pedagogy which values students' prior experiences and unique contributions to the classroom, highlights the importance of teaching rhetorical flexibility in FYW, and examines the ways cultural context influences learning and written communication. To support implementation of this pedagogy, we must infuse gateway beliefs in future faculty preparation, professional development opportunities, and WAC initiatives; in so doing, we are better equipped to open gateways between academia and students' lived experiences, thus leading to better student outcomes. [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.]