Reaching population-level impact for families in poverty requires moving beyond a sole focus on individuals, to a wider focus on interactions between individuals and their broader environmental contexts. Place-based initiatives have emerged as a policy response to promote community-level change around these broader interactions between individuals and their local communities through addressing long-standing disparities in housing, employment, education, and health. Together Growing Strong (TGS) is one such place-based initiative focused on transforming the health, wellbeing, and development of young children and their families in Sunset Park, Brooklyn. The Children, Caregivers, and Community (C3) Study is an outcomes-based study designed to assess the trajectories of children and families in Sunset Park along indicators such as family health and wellbeing and child development in relation to TGS program participation. The aims, scope, and protocol of the C3 Study are the subjects of this paper.