In discussing this question, we must not confound the rights of citizenship which a State may confer within its own limits, and the rights of citizenship as a member of the Union. It does not by any means follow, because he has all the rights and privileges of a citizen of a State, that he must be a citizen of the United States. He may have all of the rights and privileges of the citizen of a State, and yet not be entitled to the rights and privileges of a citizen in any other State. For, previous to the adoption of the Constitution of the United States, every State had the undoubted right to confer on whomsoever it pleased the character of citizen, and to endow him with all its rights. But this character of course was confined to the boundaries of the State, and gave him no rights or privileges in other States beyond those secured to him by the laws of nations and the comity of States. Nor have the several States surrendered the power of conferring these rights and privileges by adopting the Constitution of the United States. Each State may still confer them upon an alien, or any one it thinks proper, or upon any class or description of persons; yet he would not be a citizen in the sense in which that word is used in the Constitution of the United States, nor entitled to sue as such in one of its courts, nor to the privileges and immunities of a citizen in the other States. The rights which he would acquire would be restricted to the State which gave them. The Constitution has conferred on Congress the right to establish an uniform rule of naturalization, and this right is evidently exclusive, and has always been held by this court to be so. Consequently, no State, since the adoption of the Constitution, can by naturalizing an alien invest him with the rights and privileges secured to a citizen of a State under the Federal Government, although, so far as the State alone was concerned, he would undoubtedly be entitled to the rights of a citizen, and clothed with all the rights and immunities which the Constitution and laws of the State attached to that character. It is very clear, therefore, that no State can, by any act or law of its own, passed since the adoption of the Constitution, introduce a new member into the political community created by the Constitution of the United States. It cannot make him a member of this community by making him a member of its own. And for the same reason it cannot introduce any person, or description of persons, who were not intended to be embraced in this new political family, which the Constitution brought into existence, but were intended to be excluded from it.