This paper explores the historical formation of the National School Lunch Program (NSLP) in the United States and argues that programme emergence depended on the ability of policy entrepreneurs to link the economic concerns of agricultural production with the ideational concern of national security. Using a historical institutionalist framework this paper stresses the critical juncture of the Second World War and the positive feedback loop created between agricultural industries and schools to understand the emergence of the NSLP. In addition, it stresses the role of frames in policy-making and focuses on the use by policy entrepreneurs of a security frame whereby child malnutrition was cast as a national security issue. The policy window of war gave policy entrepreneurs the chance to use the politically and culturally resonant frame of security, in the contexts of agricultural subsidies, to push for the creation of this programme.