This dissertation investigates the modern American stadium from the late 1940s to the early 1980s, examining the ideologies that shaped these monumental buildings and the meanings people affixed to them. Stadiums were significant components of the modern landscape, frequently hosting massive audiences, costing tens of millions of public dollars, and uniquely symbolizing cities and their citizens’ civic spirit. Through interpretations of these stadiums’ architectural expression, spatial constitution, discursive construction, and visual representation, this study explores the ideological landscape of the modern United States, expands understandings of modern space, and examines what it meant to be “modern” throughout this period. A response to the old stadiums they replaced—largely masculine, inter-class, inter-racial, rambunctious places locked into run-down neighborhoods—new stadiums eliminated traditional and iconic sites of urban diversity, reconstituting sports spaces as modern, suburban, and technological. They re-gendered stadium space, integrating women into it as consumers and service workers. They re-classed stadium space, outfitting it with exclusive restaurants and private luxury boxes. They technologized stadium space, conspicuously loading it with exploding scoreboards and massive video screens. They re-racialized stadium space, relocating it from old ballparks adjacent dense African-American neighborhoods to open sites along freeways convenient to booming white suburbs or as anchors to clean-sweep downtown redevelopment. They fundamentally altered stadium experience, shifting emphasis from games on the field to entertainments and consumption opportunities around it. In doing all these things, modern stadiums materialized an ideological apparatus privileging a range of values and practices including gender distinction in mixed-gender settings, socio-economic and racial segregation, technological scientism, and consumption-oriented stimulation. Roy Hofheinz, the force behind the iconic Houston Astrodome’s planning and execution, fully understood the relationship of the material and the ideological; as he put it, “You’ve got to have tangibles to sell intangibles.” To illustrate these points, this dissertation engages postwar plans for futuristic new stadiums from designers like Norman Bel Geddes and Buckminster Fuller; the construction of new stadiums in the mid-1960s in New York, Houston, and St. Louis; and the increasingly routinized modern stadium of the 1970s—a controversial expression of modern progress for some, modern artificiality for others. / text