"Before the 1870s, the federal government exercised very little authority over immigration, neither establishing terms of eligibility for foreigners' admission into United States territory nor processing theirentry. Rather, the seaboard states-foremost New York and Massachusetts-administered the landing of immigrants, and each individual state determined the rights and privileges of foreigners residing within its territory. Even in the decade following the Civil War, most Americans continued to view the problems associated with mass immigration as an acceptable burden to bear in exchange for the overwhelming economic benefits reaped from the nation's traditionally liberal immigration and naturalization policy. Because such problems were understood to be local and discrete, the regulation of immigration continued to fit comfortably within the province of state police authority, under which states and municipalities regulated all aspects of public health, safety, morals, and welfare throughout the nineteenth century.' This Section maps the logic of immigration localism that shaped the regulation of non-citizens for the first half of the nineteenth century. That logic rested on two pillars: (1) a broad consensus that the regulatory challenges and political interests implicated by the presence of foreigners-the problem of economic dependency and crime, for example, or the desire to attract laborers or settlers-were fundamentally local in nature; and (2) the lack of any meaningful regulatory competition from the federal government."