This article examines how U.S. federal immigration policy in the late nineteenth century and early twentieth century regulated female immigrants who bore children outside of marriage, had sexual relations outside of marriage, or were suspected of prostitution. The author examines the ways in which immigration officials racialized the application of the moral turpitude clause in immigration law, and how this racialization reflected deeper social concerns about women's shifting economic and political roles and the definitions and expectations of marriage. Although few women were actually deported on moral turpitude grounds, patrolling women's sexuality and economic status at the borders reduced migration opportunities for women in general, subjected them to intense scrutiny by the state, constricted the contours of their personal relationships, and in some cases permanently separated them from their infant children.