During the late 1950s, physicist Frank Oppenheimer (brother of Robert) had virtually given up on science – he left academe to become a cattle rancher in Colorado after he was pursued by Sen. Joe McCarthy’s HUA-Committee and denied tenure at the University of Minnesota. But when his local Pagoda Springs High School came looking for a part-time science teacher, Oppenheimer agreed to return – and in the process, devised a "Library of Experiments" — a collection of nearly one hundred models of classical laboratory experiments which could be used in aiding the teaching of physics to elementary school children. These models became the basis for Oppenheimer’s Exploratorium – the first hands-on science museum based on a pedagogical (rather than entertainment) understanding of the value of interactive exhibits. This paper will describe Frank Oppenheimer’s vision of museums as democratizing technologies for the teaching of science and citizenship – a vision embraced by National Science Foundation policy makers as the future of K-12 science education -- and argue that his vision shaped contemporary understandings of the cultural value of museums of science and technology, as well of art, music, and history. This historical case study, therefore, enhances our understanding of the Cold War origins of informal science education, as well as the complicated relationship between popular science, culture, and the modern state.