I study one of the most profound cultural changes of the 20th century: the rise of casual dress. I study casual dress as it evolved on the beaches of Miami. I study casual dress as worn by the Black Panthers and by Princeton undergraduates. As a professor, I teach seminars on material culture and direct graduate students as they research and curate costume exhibitions, but my bread-and-butter as a scholar is the “why” and “when” our sartorial standards went from …