English Language Learners (ELLs) in the United States have been plagued by low reading achievement, high dropout rates, and overrepresentation in special education. One researched-based reading intervention, Reading Recovery®, has a large body of research supporting its effectiveness for native speakers as well as a few studies demonstrating its effectiveness for ELLs. However, there is limited research comparing the rates of progress of native English speakers with those of ELLs as well as exploring if there is a difference in outcomes between students at different English language proficiency levels. The research questions that guided this investigation are: (1) How do the reading achievement outcomes of English Language Learners receiving the intervention Reading Recovery® compare to the outcomes of native English speakers receiving the same intervention in grade one of a large diverse urban school district? (2) What is the relationship between the reading achievement outcomes and proficiency levels of English Language Learners as determined by the Reading Recovery® language proficiency intake assessment? This study employed a quantitative methodology to compare the reading achievement outcomes of students receiving the intervention Reading Recovery® in a large, urban district from 2004-2013. The analysis in this study suggests that Reading Recovery® was actually "more" effective for ELLs. Based on the results of this research study, it is recommended that access be expanded and that all low reading performing ELLs that meet the selection criteria, regardless of English proficiency, be considered for Reading Recovery®. [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.]