This chapter traces the expansion of Baltimore’s sex trade and the rise of brothel prostitution over the course of the antebellum period. Although prostitution is often called “the world’s oldest profession,” it resembled a “profession” in urban America only after the 1820s, when rapid changes to the structures of labor and increased mobility created both a supply and a demand for sexual labor beyond the structures of maritime neighborhoods. The sex trade’s geographies shifted toward new centers of business and trade, and labor patterns in the trade changed. In keeping with a broader trend of business specialization and capitalist labor practices, Baltimore’s sex trade came increasingly to revolve around brothels where madams dictated aspects of sex workers’ behavior, extracted surplus value from their labor, and commercialized both sex and intimacy to a much greater degree than before. Women involved in the sex trade adapted their ventures to cater to dominant cultural preferences, from the domestication of courting to the embrace of racially exclusionary labor practices.