Article IV, Section 2, Clause 1:
The Citizens of each State shall be entitled to all Privileges and Immunities of Citizens in the several States.
A question much mooted before the Civil War was whether the term could be held to include freed slaves and their descendants. In the Dred Scott case, 1 the Court answered it in the negative.
Citizens of each State, Chief Justice Taney argued, meant citizens of the United States as understood at the time the Constitution was adopted, and descendants of slaves
of the African race were not then regarded as capable of citizenship.  2 The only category of national citizenship added under the Constitution comprised aliens, naturalized in accordance with acts of Congress. 3 In dissent, Justice Curtis not only denied the Chief Justice's assertion that there were no slave descendants who were citizens of states in 1789 but further argued that, although Congress alone could determine what classes of aliens should be naturalized, the states retained the right to extend citizenship to classes of persons born within their borders who had not previously enjoyed citizenship and that one upon whom state citizenship was thus conferred became a citizen of the state in the full sense of the Constitution. 4 So far as persons born in the United States, and subject to the jurisdiction thereof are concerned, the question was put at rest by the Fourteenth Amendment.
At a comparatively early date, the claim was made that a corporation chartered by a state and consisting of its citizens was entitled to the benefits of the comity clause in the transaction of business in other states. It was argued that the Court was bound to look beyond the act of incorporation and see who were the incorporators. If it found these to consist solely of citizens of the incorporating state, it was bound to permit them through the agency of the corporation to exercise in other states such privileges and immunities as the citizens thereof enjoyed. In Bank of Augusta v. Earle, 5 this view was rejected. The Court held that the comity clause was never intended
to give to the citizens of each State the privileges of citizens in the several States, and at the same time to exempt them from the liabilities which the exercise of such privileges would bring upon individuals who were citizens of the State. This would be to give the citizens of other States far higher and greater privileges than are enjoyed by the citizens of the State itself. 6 A similar result was reached in Paul v. Virginia, 7 but by a different course of reasoning. The Court there held that a corporation, in this instance, an insurance company, was
the mere creation of local law and could
have no legal existence beyond the limits of the sovereignty 8 which created it; even recognition of its existence by other states rested exclusively in their discretion. Later recent cases held that this discretion is qualified by other provisions of the Constitution notably the Commerce Clause and the Fourteenth Amendment. 9 By reason of its similarity to the corporate form of organization, a Massachusetts trust has been denied the protection of this clause. 10