By the mid-twentieth century the display for profit and entertainment of people known in the United States as "freaks" had for the most part become an anachronism. Parading disabled people before a staring public for amusement has, along with public executions, become socially unacceptable. But as our lingering collective memory of P. T. Barnum suggests, from about 1830 to 1940 in the United States, as well as in Europe, people with congenital disabilities or other physical traits that could be turned into curiosities were displayed on stages, in dime museums, in circuses, and at fairs as a part of a growing culture of popular performance that was driven by the increased commercialism, leisure, and urbanization of modernity. Whereas the term "freak" now connotes a negative departure from the norm, in the nineteenth century "freak" meant a whimsical fancy. This shift in meaning suggests the long history of exhibiting...