University writing programs increasingly serve student populations of growing diversity: more international students, first-generation students, disabled students, racial and ethnic minority students, and LGBTQ+ students, for example. Instructors thus teach in classrooms with many cultures and subcultures represented. Amid increasing demographic diversity, many writing programs seek to internationalize. In this dissertation, I investigate the current state of Culturally Responsive Teaching (CRT) in a university writing program as a potential avenue for internationalization. Culturally Responsive Teaching (CRT) is a social-justice-oriented, transformative approach to education that views cultural diversity as a resource, restructuring education settings to affirm students' identities and home cultures. I evaluate CRT among a sample of 10 instructor participants and their students, propose a CRT assessment method, and suggest implementation of CRT as a sustainable, just, and resource-efficient method for writing program internationalization. I implement a mixed-methods research design that draws on both observational and self-report measures of CRT. Results indicate that instructor capabilities for CRT fall along a developmental spectrum. This developmental spectrum provides a useful model for assessment of CRT in a writing program context, as well as a basis for developing the CRT capabilities of instructors at both individual and programmatic levels. [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.]