This chapter analyzes the historicizing function of muscle building in literary naturalism and the physical-culture movement of the late nineteenth century. It begins by considering Sojourner Truth's famous baring of her muscular arm as a sign of her exemplary character and goes on to ask what kind of political promise was lodged in the transformations of muscle building. It pursues this question first through an account of the emergence of muscle as an emblem of national fitness in a variety of educational, phrenological, sociological, and political writings of the period and of its deeper roots in the rhetoric of character. It then turns to the spectacular display of muscular bodies and the rise of bodybuilding contests in the National Police Gazette and in the broader physical-culture media, focusing in particular on the ways that the muscular body destabilized the visual economy of gender and sexuality. Finally, it examine the writings of Charlotte Perkins Gilman, who was a physical-culture advocate and avid body builder, and the problematic role that muscle building plays in her utopian feminist politics and racial nationalism. The overarching aim in contrasting the visual economy of the Gazette with the narratives of Gilman is to look beyond the classificatory and disciplinary functions through which modernity's visual culture of surveillance is frequently interpreted. It does this by reading the practices of muscle building not as a commodification of the body but rather as a rehistoricization of the body, a rehistoricization that transforms the body into the visible and kinesthetic record of its own reflexive exercise.