New Jersey's Abbott Preschool program is of broad national and international interest because the Abbott program provides a model for building a high-quality system of universal pre-K through public-private partnerships that transform the existing system. The program offers high-quality pre-K to all children in 31 New Jersey communities with high levels of poverty and about a quarter of the state's children. The Abbott Preschool Program Longitudinal Effects Study (APPLES) assesses the impact of this pre-K program on children's learning and development based on a cohort of children who completed their 4-year-old year in 2004-05. APPLES previously estimated the impacts of Abbott pre-K at kindergarten entry and second grade follow-up. The 4th and 5th grade APPLES follow-up finds that Abbott preschool programs increased achievement in Language Arts and Literacy, Math, and Science. The authors' estimates indicate that two-years of pre-K beginning at age 3 had larger persistent effects on achievement than did one year of pre-K. (Contains 2 figures and 6 tables.)