Nineteenth-century America saw numerous campaigns against masturbation, which was said to cause illness, insanity, and even death. Riotous Flesh explores women's leadership of those movements, with a specific focus on their rhetorical, social, and political effects, showing how a desire to transform the politics of sex created unexpected alliances between groups that otherwise had very different goals. As April R. Haynes shows, the crusade against female masturbation was rooted in a generally shared agreement on some major points: that girls and women were as susceptible to masturbation as boys and men; that "self-abuse" was rooted in a lack of sexual information; and that sex education could empower women and girls to master their own bodies. Yet the groups who made this education their goal ranged widely, from "ultra" utopians and nascent feminists to black abolitionists. Riotous Flesh explains how and why diverse women came together to popularize, then institutionalize, the condemnation of masturbation, well before the advent of sexology or the professionalization of medicine.