In 1946, the United Nations Educational, Scientific, and Cultural Organization (UNESCO) was formed to promote peace through education and cross-cultural understanding. In the postwar atomic age, American leaders saw UNESCO and education for world citizenship as critical to the prevention of future war, the promotion of a new pluralistic vision, and the development of a well-informed society. A hyper-local case study, this article follows the story of Milton S. Eisenhower, leading UNESCO delegate and president of Kansas State College, and the series of progressive reforms he pursued to promote democracy, citizenship, and global peacebuilding at a rural land-grant college in the center of the former "isolationist belt" of America. This article traces the impact of these curricular reforms, the UNESCO campus-community partnership they inspired, and the subsequent peacebuilding movement that agitated for humanitarian action, civic participation, and desegregation from 1947 to 1950.