Over the past 30 years, state funding for public higher education has decreased dramatically in the United States ("The Chronicle of Higher Education," 2014; National Education Association (NEA), 2022). As a result, many public universities have purposefully increased international student enrollment to help replace these vanishing state funds (Bound et al., 2020; Lee & Rice, 2007; Montgomery, 2010). In my dissertation study, my broad interest was to explore college learning environments for undergraduate international students, especially those who speak English as an additional language. Using a mixed-methods approach, I examined the classroom performance as well as the environments and instruction of undergraduate international students in general education courses. The following questions guided my inquiry: GQ1. "Quantitative Focus": What have been the general education subjects on CU Boulder's campus that have the greatest number and percentage of undergraduate (visa) international student enrollment, and in which general education courses do international (visa) students tend to get the highest final grades, and is international (visa) student performance (i.e., final grades) predicted in general education courses by course- and student-level characteristics?; GQ2. "Qualitative Focus": In select general education courses, how do instructors and international students experience their classroom environments and instruction, and how do international students, especially those learning English as an additional language, perceive the instructional features used in their classrooms? What features of linguistic responsiveness, if any, are valued and enacted by instructors in these classrooms?; and GQ3. "Normative Focus": How well does the Linguistically Responsive Teaching Framework (LRTF, Lucas & Villegas, 2011) designed for U.S. K-12 classrooms account for undergraduate instructors and multilingual EAL international students' course experiences? Should the LRTF (2011) be adapted for use by university educators in undergraduate education to inform and guide their practice, and if so, how? To address GQ1, I cleaned and analyzed a large dataset I received from CU Boulder's Office of Data Analytics (ODA) that ultimately included the final grades of 3,927 international (visa) students in 336 general education courses. For GQ2, I analyzed audio recordings of undergraduate instructors and international students as well as general education classroom observation notes and artifacts. And for GQ3, I combined the analysis and findings inspired by GQ1 and GQ2 to argue that while Lucas and Villegas' (2011) original LRTF accounted for many of the instructor and student course experiences, my findings point to several aspects of higher education classrooms that warrant further attention when aspiring to linguistically responsive instruction, for example class size and year, students' full linguistic capabilities, student interactions, and first-year student status. In the last chapter, I present a new undergraduate LRTF for higher education designed to encourage and support undergraduate instructors not only when reflecting on their classroom instruction of multilingual EAL international students but also when they make choices about their course curriculum. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]