American architect Victor Lundy designed an inflatable pavilion to house the traveling Atoms for Peace exhibition in 1960. This pavilion constituted a literal atmosphere because the difference between its internal and external air pressure functioned as the structural element. The pavilion also produced an experiential atmosphere that, like the exhibition within, used technological progress to suggest a better world to come. In this paper, I recover the little-known history of Lundy’s pavilion to expand its atmospheric dimensions to include not only the literal and experiential but also the sociopolitical. Such an expansion reveals the ideological pressures that shaped the pavilion and, more generally, the changing meanings of inflatable architecture during the postwar period.