The present study assessed the effects of a specialized first-year foundations course as an intervention for international students' academic and cultural adaptation at a large, Midwestern, public research institution (very high research activity). This was a quasi-experimental, mixed methods study, consisting of two quantitative and two qualitative analyses. The results of the quantitative analyses indicated that participation in the first-year foundations course significantly (p [less than or equal] 0.002) improved students' academic skills, including writing, delivering effective presentations, and summarizing main ideas from existing sources. In addition, participation in the course resulted in positive (p [less than or equal] 0.05) changes in students' independent learning, self-analysis, and goal-setting abilities. One of the more encouraging findings of this study was participants' increased understanding of social diversity in the United States, as well as an increased (p [less than or equal] 0.05) comfort level with individuals of diverse backgrounds. Quasi-experiment participants also utilized university resources and services more frequently than the control group participants (p [less than or equal] 0.05), and were more academically and socially engaged (p [less than or equal] 0.05). Of particular importance was participants' more frequent interaction with American students, both inside and outside the classroom (p [less than or equal] 0.05). The qualitative analyses of this study discovered distinct challenges faced by international students, determined by differences in educational systems, as well as differences in cultural norms and expectations. The analyses also identified various sources of motivation utilized by study participants and shed light on the peculiarities of their acculturation process. In addition, the qualitative portion of the study identified aspects of psychosocial development and strategies for academic success essential to international student adaptation. Implications for higher education policy makers and suggestions for future research are discussed. [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/en-US/products/dissertations/individuals.shtml.]