The purpose of the current study is to shed a light on institutional internationalization efforts and undergraduate students' global learning outcomes in four-year higher education institutions in the United States exploring the topic at the student, institutional, and academic-major levels. Specifically, three research questions lead the study: (1) What is the relationship among "student characteristics," global engagement indicators (e.g., interactional international diversity, programmatic international diversity), and global learning outcomes? (2) What is the relationship among "institutional characteristics," global engagement indicators (e.g., interactional international diversity, programmatic international diversity), and global learning outcomes? and (3) What is the role of academic majors in providing student global learning outcomes? Merging data from the National Survey of Student Engagement (NSSE), The Integrated Postsecondary Education Data System (IPEDS), and NAFSA: Association of International Educators, I first built two separate SEM/path analytic models based on Gurin's (1999a) three-tiered model of structural, informal interactional, and classroom diversity to address the first two research questions. Gurin's model is commonly adopted to understand domestic diversity in U.S. higher education and how U.S. institutions can create opportunities for students to become aware of diversity and participate in experiences with diverse content and individuals. Such a concurrent and multi-level domestic diversity approach has been fundamental to creating diverse and welcoming environments for students, resulting in positive student development outcomes in various domains including cognitive, practical competence and skills, and personal development (Chang, 1999; Gurin, 1999a; 1999b; Gurin et al., 2002). By adapting Gurin's (1999a) model to international education, I aimed to capture not only the relationship of student and institutional characteristics to student global learning outcomes but also the ways in which student engagement in internationalization activities mediate those relationships. Additionally, academic majors serve as key contextual factors that can affect differences in the student experience and learning outcomes. Therefore, to address the third research question, students' academic majors were incorporated into the assessment of student global learning by building on Biglan's (1973a) theoretical classification of academic majors, a seminal work in the academic curriculum literature. Biglan's (1973a) classification proposes that students' enculturation, learning experiences, and outcomes are influenced by disciplinary discourses in addition to student-level differences. I developed a multi-level model to examine the relationship between Biglan's academic major types and global learning outcomes, how major-level predictors may explain the variation between Biglan's categories of academic majors and global learning outcomes, and the relationship between student-level factors and global learning outcomes while accounting for major-level effects. Overall, bringing the student, institutional, and academic major aspects together, the study contributes to the topic of internationalization practices by shedding light on contextual factors that may have a role in shaping student experiences in U.S. higher education. Findings were discussed in the realm of higher education with implications for practice and future research. [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.]