The landmark New Jersey Supreme Court school funding case, "Abbott v. Burke", established the availability of preschool for all three- and four-year-olds living within the state's thirty-one poorest districts as a means of eradicating the effects of poverty. Longitudinal studies have shown the value of high quality preschool programs for improving student achievement, immediately and well into adulthood. This quantitative study examines the sustainability of the benefits of high-quality preschool in an Abbott District. This research examines to what extent academic achievement in third grade is influenced by continuous enrollment, by comparing the differences in academic outcomes between students who have a history of continuous enrollment in the same school and those who have changed schools since preschool or those who have never attended preschool in the district. Links between participation in preschool and mobility support the contention that preschool participation positively impacts student achievement, while mobility negatively impacts the sustainability of benefits. Seven questions guided the researcher in investigating how the interaction of preschool participation and socioeconomic status, gender, mobility, absences; and a school's No Child Left Behind (NCLB) status affects the sustainability of benefits through the third grade, as measured by the State-mandated assessment in language arts literacy and mathematics. Results align with the literature and identify participation in a quality preschool program as a primary factor affecting student achievement Findings captured pertinent information as to how participation in a quality preschool is sustained through the third grade, especially for students who remain at the same school. Mobility negatively impacts student achievement and the sustainability of benefits of preschool participation. This study revealed that the school's NCLB status is negatively associated with the benefits of preschool participation. The sustainability of benefits for students enrolled in schools that failed to meet the adequate yearly progress, as monitored by NCLB Legislation, is lower than for students enrolled in schools that meet all the requirements. Additionally, when a school fails to meet NCLB's requirements for three years in a row, the benefits are sustained the least, and once the school implements interventions, students' achievement improves. As schools start to implement interventions to change the school's status, student achievement is better sustained all the way through the third grade Student attendance, gender, and socioeconomic status do not affect the sustainability of the benefits of preschool participation. In summary, the academic benefits of preschool participation are sustained through the third grade, but when students move between schools the benefits decrease. [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.]