This talk describes the evolution of the Fragile Families and Child Wellbeing study (FF), a national U.S. birth cohort study that is headquartered at Princeton University, from its preconception period through development, maturity, and expansion. FF is the longest running (and only ongoing) birth cohort study in the U.S. that is based on a national probability sample (i.e., is representative of a population). The talk relates how the project got started, how it developed, and how it has become a unique and increasingly valuable national resource for learning about poverty and family functioning, linkages between socioeconomic status and health, and determinants of intergenerational mobility and income inequality.