"This Article challenges the central orthodoxy of modem constitutional immigration law that the regulatory authority to which an immigrant is subject properly hinges on her citizenship status. It argues that, notwithstanding its aura of naturalness, the legal construction of foreignness that underwrites the inherent sovereignty rationale did not take shape in its recognizably modem form until the 1880s. Throughout the nation's first century, immigrants' non-citizenship was incidental, or at least secondary, to the nature of the regulatory authority to which they, as immigrants, were subject. The reasons for this lie largely outside of the law. Until the decades following the Civil War, most Americans shared abroad confidence both in immigrants' moral natures and in the power of American economic and political institutions to transform them into patriotic republicans. During this era of relative confidence, the individual states reserved significant authority over immigrants and immigration under their traditional police powers. State police authority, in turn, depended not on immigrants' status as foreigners, but rather on the purpose of the particular regulation at issue. As the objects of the state police power-as potential paupers or carriers of disease, for example-immigrants were simply persons, whose effect on the health, morals, and welfare of the community was, like that of all persons, native and foreign alike, subject to regulation. Even after the Supreme Court re-branded immigrants as articles of commerce in the 1870s to accommodate the transfer of regulatory authority from the individual states to Congress, it did not distinguish between human commercial goods transported from a neighboring state and those transported across an ocean. The Commerce Clause, like the police power, was indifferent to citizenship."