..."We have in our political system a government of the United States and a government of each of the several States. Each one of these governments is distinct from the others, and each 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 these governments will be different from those he has under the other. Slaughter-House Cases, 16 Wall. 74.

"Citizens are the members of the political community to which they belong. They are the people who compose the community, and who, in their associated capacity, have established or submitted themselves to the dominion of a government for the promotion of their general welfare and the protection of their individual as well as their collective rights. In the formation of a government, the people may confer upon it such powers as they choose. The government, when so formed, may, and when called upon should, exercise all the powers it has for the protection of the rights of its citizens and the people within its jurisdiction; but it can exercise no other. The duty of a government to afford protection is limited always by the power it possesses for that purpose.

"Experience made the fact known to the people of the United States that they required a national government for national purposes. The separate governments of the separate States, bound together by the articles of confederation alone, were not sufficient for the promotion of the general welfare of the people in respect to foreign nations, or for their complete protection as citizens of the confederated States. For this reason, the people of the United States, "in order to form a more perfect union, establish justice, insure domestic tranquillity, provide for the common defence, promote the general welfare, and secure the blessings of liberty" to themselves and their posterity (Const. Preamble), ordained and established the government of the United States, and defined its powers by a constitution, which they adopted as its fundamental law, and made its rule of action.

"The government thus established and defined is to some extent a government of the States in their political capacity. It is also, for certain purposes, a government of the people. Its powers are limited in number, but not in degree. Within the scope of its powers, as enumerated and defined, it is supreme and above the States; but beyond, it has no existence. It was erected for special purposes, and endowed with all the powers necessary for its own preservation and the accomplishment of the ends its people had in view. It can neither grant nor secure to its citizens any right or privilege not expressly or by implication placed under its jurisdiction.

"The people of the United States resident within any State are subject to two governments: one State, and the other National; but there need be no conflict between the two. The powers which one possesses, the other does not. They are established for different purposes, and have separate jurisdictions. Together they make one whole, and furnish the people of the United States with a complete government, ample for the protection of all their rights at home and abroad. True, it may sometimes happen that a person is amenable to both jurisdictions for one and the same act. Thus, if a marshal of the United States is unlawfully resisted while executing the process of the courts within a State, and the resistance is accompanied by an assault on the officer, the sovereignty of the United States is violated by the resistance, and that of the State by the breach of peace, in the assault. So, too, if one passes counterfeited coin of the United States within a State, it may be an offence against the United States and the State: the United States, because it discredits the coin; and the State, because of the fraud upon him to whom it is passed. This does not, however, necessarily imply that the two governments possess powers in common, or bring them into conflict with each other. It is the natural consequence of a citizenship which owes allegiance to two sovereignties, and claims protection from both. The citizen cannot complain, because he has voluntarily submitted himself to such a form of government. He owes allegiance to the two departments, so to speak, and within their respective spheres must pay the penalties which each exacts for disobedience to its laws. In return, he can demand protection from each within its own jurisdiction.

"The government of the United States is one of delegated powers alone. Its authority is defined and limited by the Constitution. All powers not granted to it by that instrument are reserved to the States or the people. No rights can be acquired under the constitution or laws of the United States, except such as the government of the United States has the authority to grant or secure. All that cannot be so granted or secured are left under the protection of the States.