Children's healthy mental development has never been the focus of long-term, committed public health policy in the way that early physical health and development have been. We discuss four types of societal response to illness—cure, care, control, and prevention—and trace the history of public health in terms of its special responsibility to control and prevent disease. We identify four periods in the history of public health: the Sanitarian era (up to 1850), the Bacterial era (1850–1950), the Behavioral era (1950–present), and the Communitarian era (the next century). Looking at this history from the viewpoint of the developmental psychopathology of the first 2 decades of life, we trace progress in public health responses to children with mental illness, from a philosophy of control by isolation toward one of preventive intervention. We examine primary, or universal, prevention strategies that have been tried, and we suggest some that might be worth reconsidering.