This quantitative study examines the relationship between implementation of the 21st Century Afterschool Centers on Education (ACE) program and fourth grade student performance on the State of Texas Assessment of Academic Readiness (STAAR). Data collection was extracted from schools within South Texas. The campus variation chosen for this study involved those implementing the ACE program as well as non-ACE campuses. Data was obtained through the 2018-2019 Texas Academic Performance Report (TAPR) published by Texas Education Agency (TEA) for each campus. This was completed to assess academic achievements in Reading, Math and Writing on The State of Texas Assessments of Academic Readiness (STAAR). The study applied a quantitative, ex-post facto research approach that analyzed data from fourth grade students enrolled in elementary schools in South Texas. Results of the study found no significant difference on STAAR performance between elementary schools which implemented the ACE program and those which did not. Conclusions and implications are discussed as well as recommendations for future research. [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.]