The Future of Families and Child Wellbeing Study (FFCWS), formerly known as the Fragile Families and Child Wellbeing Study, is a comprehensive longitudinal dataset following nearly 5,000 children born in large U.S. cities between 1998-2000. Led by researchers including Sara McLanahan, Irwin Garfinkel, and Kathryn Edin at Princeton University, the study was designed to address four key questions: the conditions of unmarried parents (particularly fathers), nature of family relationships, child wellbeing outcomes, and impacts of policies and environmental factors. What makes this dataset unique is its oversampling of births to unmarried parents (3:1 ratio), resulting in disproportionate representation of Black, Hispanic, and low-income families. The study collects extensive data from both mothers and fathers through multiple waves of interviews at children's ages 1, 3, 5, and beyond. It also includes in-home assessments and biological data, making it the only U.S. population-based birth cohort study currently following three generations of family members. This rich dataset serves as a critical resource for researchers studying family structure, child development, poverty, and social policy impacts, providing invaluable insights into how various family arrangements affect long-term child outcomes.