The purposes of this exploratory survey research are: (1) to examine the degree to which best practices on language acquisition instructional strategies and resources are used across the ten schools in Monroe County School District (MCSD), (2) to understand the relationship teachers' preparation and background characteristics and language acquisition instructional strategies and resources, and (3) to investigate how the use of effective strategies and resources are associated with academic achievement and achievement growth of English Learners in MCSD. Closing the achievement gap between English Learners and their White native English-speaking peers has been a priority for the Monroe County School District (MCSD). Although instructional quality is critical for achievement of English Learners, little is known about what language acquisition instructional strategies and resources have been used by teachers of English Learners across ten schools in MCSD. Based on a districtwide survey of 169 teachers across 10 schools, I found that Hispanic teachers are significantly more likely to use effective instructional strategies and resources to assist English Learners. The study also found that teachers were more likely to use the effective instructional strategies and resources if they have attended an AVID, ELLevation, and WIDA professional development opportunity. Another significant finding is that secondary teachers are less likely than elementary teachers to use effective instructional strategies and resources. Recommendations and findings were shared with the Monroe County School District leadership team. [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.]