Sexuality was critical to how individuals experienced, learned, and contested their place in early America. Regulating Passion shows the sweeping changes that affected the social and political morass centered on sexual behavior during the late eighteenth and early nineteenth centuries in Massachusetts-even as patriarchy remained important to those configurations of power. Charting the governments and societys management of sexuality, Kelly A. Ryan uncovers the compelling stories of the individuals charged with sexual crimes and how elites hoped to contain and exploit illicit sexual behavior. In the colonial era, elites designed laws, judicial and religious practices, and sermons that defined certain groups as criminal, the cause of sexual vice, and in need of societal oversight-while defining others as chaste and above reproach. Massachusetts fornicators, adulterers, seducers, and rapists were exemplars of improper behavior in the colonial era and were central to emerging sexual subjectivities associated with gender, race, and class status in the early republic. As Massachusetts modernized, culture and socialization became vehicles for enforcing the marital monopoly on sex and gendered expectations of sexual behavior. The American Revolution saw the decline of direct sexual regulation by government and religious institutions and a rise in the importance of sexual reputation in maintaining hierarchy. As society moved away from publicly penalizing forms of illicit sexual behavior, it circulated ideas about sexual norms, initiated social ostracism, and interceded with family and friends to promote sexual morality, even as the government remained involved in cases of prostitution and interracial sex. At the same time, this transformation in sexual regulation opened up means to contest the power of patriarchy. Women, African Americans, Indians, and the poor often resisted the efforts of elites and established their own code of sexual conduct to combat ideas about what constituted sexual virtue and how society defined its leaders. They challenged derisive sexual characterizations, patriarchal visions of society, and sexual regulation to establish a space in the body politic. Ironically, their efforts often reinforced patriarchal ideals as their petitions asked for patriarchal privileges to be extended to them. Based on records of crimes in lower and upper courts, print literature, and other documentary sources, Regulating Passion underscores the ways in which sexual mores remained essential to the project of differentiating between the virtue of citizens and contesting power structures in the tumultuous transitions from the colonial to early national period.