In 1972, childfree activists Ellen Peck and Shirley Radl founded the National Organization for Non-Parents (NON), the first organization dedicated to defending the rights of the “childless by choice.” Emerging at the nexus of identity politics and environmental activism, NON promoted childfree living as both a socially respectable and politically responsible reproductive choice. This article traces NON’s evolution from a grassroots movement to a professionalized activist organization. Beyond arguments about the urgency of population control, NON offered a sophisticated critique of the marginalization of childless citizens in an intensely pronatalist society. Childfree activists faced fierce opposition from those who believed that reproduction and parenthood were defining features of the American family. By embracing the language of reproductive choice, NON was able to ameliorate some of the controversy that surrounded its childfree crusade and bring voluntary childlessness into the mainstream of American thought.