The academic achievement gap between ethno-linguistic minority students and other students, as represented by test scores, dropout rates, and college admissions and completion rates, is the most persistent and pressing challenge facing public schools nationwide. The existing achievement gap indicates that many of our students are not receiving the minimum education needed to become literate and join the labor market. The resulting opportunity cost of lost income from unemployment and low paying jobs has important ramifications for our society. The compilation of research suggests that English language learners must acquire English to a level of proficiency that maximizes their capacity to successfully engage in content area instruction delivered in English. This task not only requires English Language Learners (ELLs) to acquire English, but use their new language in increasingly sophisticated ways. The identification and implementation of research-based curriculum and instruction towards this end enables the public education system to be the greatest equalizer in our society. This study employed a quasi-experimental, quantitative model using the California Standards Test, the California High School Exit Exam, and the California English Language Development Test (CST, CAHSEE, and CELDT) to evaluate the efficacy of the "High Point" Curriculum in the Coastline Unified School District (CUSD). "High Point" is a research-based intervention program designed to accelerate growth in language and literacy for ELL students. Compared to two schools over four years on the CST ELA and the CAHSEE, the results of the analysis indicate that the ELLs in CUSD's "High Point" intervention school may have benefited from exposure to the "High Point" curriculum. All three schools demonstrated substantial gains on the CELDT; however, the gains in the "High Point" intervention school were less than those of the comparison schools. [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.]