The purpose of this study was to examine the sustained impact of participation in the Tools of the Mind preschool program on language arts, mathematics, reading and writing achievement in middle school, the specific impact of participation on racial subgroups and socioeconomically disadvantaged students, and the effects of student mobility on academic achievement. Using a nonexperimental, quantitative, longitudinal design, the achievement of the original cohort of students who participated in the program was examined over 2 consecutive years. The results of the study suggest that participation in the Tools of the Mind program increases the overall achievement of socioeconomically disadvantaged students and the writing performance of African American students. Analysis of student mobility data revealed that a high rate of student mobility has a negative impact on student achievement. These study results are consistent with decades of research into the impact of participation in a high-quality preschool program. Caution should be taken in interpreting the results because promotion of the development of self-regulation and executive function, aspects that set the Tools of the Mind program apart from other preschool programs, is not measured by the NJASK, and thus the impact of the program may have been underestimated.