In the early days of television, suburban families welcomed TV into their homes as an electronic babysitter that would also teach their children about the world. Children's programming soon came to play a key role in the development of mass culture, promoting the shared interests, norms and vocabulary through which children interact with peers and define themselves as a cohort. This social history examines the forces driving the development of children's television in the U.S., from its inception to the present. Analyses of iconic programs reveal how they influenced our concept of childhood.