There is in our political system a government of each of the several States, and a Government of the United States. Each is distinct from the others, and has citizens of its own who owe it allegiance, and whose rights, within its jurisdiction, it must protect. The same person may be at the same time a citizen of the United States and a citizen of a State, but his rights of citizenship under one of those governments will be different from those he has under the other.

United States v. Cruikshank, 92 U.S. 542 (1875)