This dissertation explores how afterschool programming shaped New York City children's experiences from the 1930s-1960s. Centering the many organizations that planned activities for children, I explore the beliefs and institutional dynamics that determined what the work of afterschool involved. With purposes spanning education, recreation, physical and mental health, childcare, assimilation, racial equity, and more, afterschool was both a practical resource and a place to imagine what urban childhood should look like. It became part of the landscape of New York City neighborhoods, inhabiting schools, settlement houses, community centers, storefronts, churches, and housing. By framing afterschool as a resource and investigating how it was administered and operated, we see that it could provide unprecedented opportunities, but it was not distributed fully and equitably. Designated as a supplemental service for parents and schools that lacked other options, afterschool has long been called upon to fix social and educational problems without sufficient funding or attention. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]