This study examines how changes in the growth model of the US sports business since World War II—namely, changes in stadium design and ticket sales strategies—have transformed the accessibility of major league stadiums and the class composition of the fans inside. While survey data show an overrepresentation of wealthy fans in stadiums at the end of the twentieth century, they reveal little about whether or not this was a new phenomenon. I use ticket sales data to demonstrate that the displacement of working-class fans by the relatively affluent began in earnest at least as early as the 1950s. Before “premium-seating” options like luxury boxes became the norm, the expanded sale of season-ticket packages requiring large up-front payments made it more difficult for wage earners to attend games. While this crowding out of working-class fans has a longer history than very recent outcries over “stadium gentrification” suggest, it has intensified significantly over the last quarter century. Using an original data set containing information on seating arrangements at both the current and previous facilities of 73 of 91 active Major League Baseball, National Basketball Association, and National Football League franchises, this article offers the first systematic evidence in support of claims that the proliferation of luxury suites and other exclusive seating options has resulted in the subtraction of large numbers of relatively affordable seats. This research not only deepens our understanding of the history of urban gentrification and postwar consumption, but also has important implications for the ongoing debate over public stadium subsidies.