The demographic changes in the U.S. have contributed to linguistic, cultural, and ethnic diversification of today's society; however, monolingual ideologies continue to define many societal and academic discourses due to their historical roots (Matsuda, 2006; Wiley, 2014). One area of higher education that this trend is observed is academic writing. Scholars in the field of second language writing have pointed out that a monolingual orientation shifts the responsibility to address language diversity onto students and often results in making international students, who speak English as an Additional Language (EAL), left feeling outside the academic community. This dissertation examines the context and roots of tensions between the multilingual attributes of international students and monolingual ideologies by locating them in a first-year EAL academic writing curriculum. The study inquires whether students exhibit ideologies with respect to language identity and if so, in what ways it might relate to each individual student's academic positioning. To answer these overarching research questions, interviews and observations were conducted over a period of four months during the academic semester, engaging eight students, the course instructor, and the directors of the undergraduate EAL and composition programs. To increase the trustworthiness, the dissertation included additional data such as syllabi of the first-year EAL and domestic academic writing curricula, students' previously completed course needs analysis survey results, final course reflection essays, research report outlines/first drafts, and final drafts. The study's theoretical framework draws on two concepts, multilingual proficiency (Brutt-Griffler, 2017) and investment (Norton, 1997; 2013). The former describes English learner's legitimate ownership of English as part of their multilingual knowledge, and the latter describes language learning as both an investment of time and effort, and a process of social identity development. In analyzing data, process coding (Charmaz, 2002) and pattern coding (Saldana, 2016; Miles et al., 2014) were employed, incorporating inductive and deductive approaches (Hyde, 2000; Kirk & Miller, 1986). The research study finds that the first-year EAL academic writing curriculum provided adequate education that meets the academic and linguistic needs of the students, through cooperating with the domestic academic writing curriculum. The students revealed their continual identity development as legitimate multilingual members with clear academic and career goals. However, the systematic isolation of the EAL program within the institution revealed its contribution to the students' perceived inferiority in their academic English identity as non-native speakers in the non-EAL context of the institution (cf. Cui, 2019; Matsuda, 2006; Marshall, 2010). The study revealed the ideological dichotomy with respect to the EAL program's struggle to be integrated into the institution and the institutional marginalization of the EAL program, underscoring a lack of recognition of the multilingual attributes of international students and continual neglect of their academic supports in English knowledge development. At the same time, this research study sheds light on the constructive orientation of an EAL program to cooperate with a non-EAL curriculum in a monolingual higher education context and the potential of EAL programs as a means to move away from the institutional monolingualism and promotion of international students' full academic membership and positive language learning experience. This dissertation research, therefore, puts forth a recommendation to U.S. higher education institutions to establish a shared-responsibility model of multilingual education with their EAL programs. [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.]