Contributions of the Project Competence Longitudinal Study (PCLS) to resilience science and developmental psychopathology are highlighted in this article. Initiated by Norman Garmezy, the PCLS contributed models, measures, and methods, as well as working definitions of concepts like competence, developmental tasks, protective factors, and resilience. Findings from the study corroborated the feasibility of studying adaptation in a normative group of school children, identifying patterns of resilience, competence without major adversity, and maladaptive paths through life. Competence was multidimensional, showing continuity and change over time. Cascading effects across domains indicated that competence and problems spread over time. Thus, adult achievements in developmental tasks were rooted in childhood and adolescence. Young people who showed resilience had much in common with similarly successful peers who experienced less adversity over time, including high-quality relationships with parents and other adults, and good cognitive, as well as social-emotional, skills. Maladaptive youth in the study often faced high adversity with little adaptive capacity (internal or external) and tended to generate stressful experiences. Resilience often emerged in childhood and endured, but there also were late bloomers whose lives turned around in the transition to adulthood. The role of collaboration and mentorship in the PCLS is also discussed.