The Chicago Longitudinal Study investigates the life course development of 1539 children (93% African American and 7% Hispanic) who were born in 1979-1980, grew up in the highest-poverty neighborhoods in Chicago, and attended early childhood intervention programs beginning in preschool. The goals of the study are to determine the effects of participation in the Child-Parent Center Program, document patterns of child and family well-being over time and identify child, family, school and community factors that can promote children's well being. We describe major intervention findings of the study and summarize the contributions of a variety of personal, family, and school experiences in promoting long-term educational and social success.