It is not the province of the court to decide upon the justice or injustice, the policy or impolicy, of these laws. The decision of that question belonged to the political or law-making power; to those who formed the sovereignty and framed the Constitution. The duty of the court is, to interpret the instrument they have framed, with the best lights we can obtain on the subject, and to administer it as we find it, according to its true intent and meaning when it was adopted.

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.

The question then arises, whether the provisions of the Constitution, in relation to the personal rights and privileges to which the citizen of a State should be entitled, embraced the negro African race, at that time in this country, or who might afterwards be imported, who had then or should afterwards be made free in any State; and to put it in the power of a single State to make him a citizen of the United States, and endue him with the full rights of citizenship in every other State without their consent? Does the Constitution of the United States act upon him whenever he shall be made free under the laws of a State, and raised there to the rank of a citizen, and immediately clothe him with all the privileges of a citizen in every other State, and in its own courts?

The court think the affirmative of these propositions cannot be maintained. And if it cannot, the plaintiff in error could not be a citizen of the State of Missouri, within the meaning of the Constitution of the United States, and, consequently, was not entitled to sue in its courts.

It is true, every person, and every class and description of persons, who were at the time of the adoption of the Constitution recognised as citizens in the several States, became also citizens of this new political body; but none other; it was formed by them, and for them and their posterity, but for no one else. And the personal rights and privileges guarantied to citizens of this new sovereignty were intended to embrace those only who were then members of the several State communities, or who should afterwards by birthright or otherwise become members, according to the provisions of the Constitution and the principles on which it was founded. It was the union of those who were at that time members of distinct and separate political communities into one political family, whose power, for certain specified purposes, was to extend over the whole territory of the United States. And it gave to each citizen rights and privileges outside of his State which he did not before possess, and placed him in every other State upon a perfect equality with its own citizens as to rights of person and rights of property; it made him a citizen of the United States.

It becomes necessary, therefore, to determine who were citizens of the several States when the Constitution was adopted. And in order to do this, we must recur to the Governments and institutions of the thirteen colonies, when they separated from Great Britain and formed new sovereignties, and took their places in the family of independent nations. We must inquire who, at that time, were recognised as the people or citizens of a State, whose rights and liberties had been outraged by the English Government; and who declared their independence, and assumed the powers of Government to defend their rights by force of arms.

In the opinion of the court, the legislation and histories of the times, and the language used in the Declaration of Independence, show, that neither the class of persons who had been imported as slaves, nor their descendants, whether they had become free or not, were then acknowledged as a part of the people, nor intended to be included in the general words used in that memorable instrument.

It is difficult at this day to realize the state of public opinion in relation to that unfortunate race, which prevailed in the civilized and enlightened portions of the world at the time of the Declaration of Independence, and when the Constitution of the United States was framed and adopted. But the public history of every European nation displays it in a manner too plain to be mistaken.

They had for more than a century before been regarded as beings of an inferior order, and altogether unfit to associate with the white race, either in social or political relations; and so far inferior, that they had no rights which the white man was bound to respect; and that the negro might justly and lawfully be reduced to slavery for his benefit. He was bought and sold, and treated as an ordinary article of merchandise and traffic, whenever a profit could be made by it. This opinion was at that time fixed and universal in the civilized portion of the white race. It was regarded as an axiom in morals as well as in politics, which no one thought of disputing, or supposed to be open to dispute; and men in every grade and position in society daily and habitually acted upon it in their private pursuits, as well as in matters of public concern, without doubting for a moment the correctness of this opinion.