A persistent achievement gap exists between the steadily growing population of adolescent English language learners (ELLs) in K-12 public schools and their native English-speaking peers. Unsurprisingly, the underachievement of this population of students is linked to an excessively high dropout rate among adolescent ELLs across the nation. Current research highlights the critical need for instructional approaches that support these learners in developing academic English and advanced literacy practices. Through research-based effective instructional practices that support the attainment of advanced literacy practices, these culturally and linguistically diverse learners are afforded access to post-secondary educational and career opportunities from which they are otherwise excluded. A growing body of research suggests that genre-based pedagogy is an effective instructional approach for apprenticing adolescent ELLs into academically-valued writing practices across school-based genres. Drawing on this research, this study employed a pretest/posttest design to investigate the effect of the genre-based Reading to Learn approach, grounded in systemic functional linguistics, on adolescent ELLs' competency in writing academically successful persuasive argument essays. Following an ethnographic approach, this study also investigated the way that the participants perceived the effects of the "Reading to Learn" approach on their development as a second language writers. Finally, this study aimed to richly describe the challenges of designing and implementing an instructional intervention using the "Reading to Learn" approach in an urban public high school English as a Second Language (ESL) classroom. Findings indicate that the "Reading to Learn" approach had a significant effect on the participants' competency for writing academically-valued persuasive argument essays. Despite challenges in designing and implementing an instructional intervention using the "Reading to Learn" approach, these findings contribute to the growing body of evidence that suggests that this genre-based instructional framework may support adolescent ELLs' progress toward the development of advanced literacy practices. [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.]