Clause 4 of Section VIII of Article I of the Constitution gives to Congress the power to establish "an uniform rule of naturalization."

This power has already been considered in an earlier chapter dealing with citizenship, and it is here necessary to add only that the power, though in an early and ill considered case held to be one that may be concurrently exercised by the States,1 was in Chirac v. Chirac,2 decided in 1817, held to be exclusively in Congress and this doctrine has not since been questioned.