Cousin marriage, hierarchy, and heredity: contestations over domestic and national body politics in 19th-century America

How did cousin marriage-an institution that had been not only common, but also emotionally resonant, culturally validated, and economically productive in America-come to be recast as emotionally repugnant, medically dangerous, and politically backward? This paper follows 19th-century opponents of cousin marriage who framed their argument by positing a concordance between marital types (inversus out-marriage) and political types (monarchical versus republican). In the language of humoral medicine, these arguments recalibrated the previously positive associations between cousin marriage and hierarchical systems of hereditary rank by linking it to ideas about ill health and the degeneration and decline of family lines and European monarchies. Simultaneously, the negative evaluation of marital mixing across ranks and between populations was dismantled by correlating out-marriage with the egalitarian ideals of republicanism and connecting it with the positive values of health, vitality, and progress-of individuals, family lines, and the new American republic-a connection that was, however, contradicted by the racial politics of antebellum America.