The purpose of this study was to determine the effect of participation in the district's early childhood program on later academic achievement as measured by the State of Texas Assessment of Academic Readiness (STAAR) mathematics and reading assessments in Grades 3, 4, and 5. The studied district opened a centralized early childhood school in 2009 and implemented the Texas Pre-K Guidelines. The STAAR test results were available for five cohorts of students who attended the early childhood school and took the STAAR mathematics and reading assessments in the years 2014-2018. A quasi-experimental design was used to analyze differences in STAAR mathematics and reading scores for students who attended the district's early childhood program and students who did not attend. A two-way factorial ANOVA was used to examine the effect on test scores of attending the district's early childhood school and other demographic categories, Latinx, African American, socio-economic status, and English language learners (ELL). The results show that attending the early childhood program did not have a statistically significant effect for Latinx or African American students. However, the mean mathematics scores for economically-disadvantaged students who attended the early childhood program were higher than their peers who did not attend. ELL students who attended the program also had higher mathematics scores but the differences were usually not statistically significant. The same impact on economically-disadvantaged students and ELLs was not found on reading tests.