The Qualities of a Citizen traces the application of U.S. immigration and naturalization law to women from the 1870s to the late 1960s. Like no other book before, it explores how racialized, gendered, and historical anxieties shaped our current understandings of the histories of immigrant women. The book takes us from the first federal immigration restrictions against Asian prostitutes in the 1870s to the immigration "reform" measures of the late 1960s. Throughout this period, topics such as morality, family, marriage, poverty, and nationality structured historical debates over women's immigration and citizenship. At the border, women immigrants, immigration officials, social service providers, and federal judges argued the grounds on which women would be included within the nation. As interview transcripts and court documents reveal, when, where, and how women were welcomed into the country depended on their racial status, their roles in the family, and their work skills. Gender and race mattered. The book emphasizes the comparative nature of racial ideologies in which the inclusion of one group often came with the exclusion of another. It explores how U.S. officials insisted on the link between race and gender in understanding America's peculiar brand of nationalism. It also serves as a social history of the law, detailing women's experiences and strategies, successes and failures, to belong to the nation.