Article 4, Section 2, Clause 1
Joseph Story, Commentaries on the Constitution 3:§§ 1799--18001833
§ 1799. The first is, "The citizens of each state shall be entitled to all privileges and immunities of citizens in the several states." There was an article upon the same subject in the confederation, which declared, "that the free inhabitants of each of these states, paupers, vagabonds, and fugitives from justice excepted, shall be entitled to all privileges and immunities of free citizens in the several states; and the people of each state shall, in every other, enjoy all the privileges of trade and commerce, subject to the same duties, impositions, and restrictions, as the inhabitants thereof respectively," &c. It was remarked by the Federalist, that there is a strange confusion in this language. Why the terms, free inhabitants, are used in one part of the article, free citizens in another, and people in another; or what is meant by superadding to "all privileges and immunities of free citizens," "all the privileges of trade and commerce," cannot easily be determined. It seems to be a construction, however, scarcely avoidable, that those, who come under the denomination of free inhabitants of a state, although not citizens of such state, are entitled, in every other state, to all the privileges of free citizens of the latter; that is to greater privileges, than they may be entitled to in their own state. So that it was in the power of a particular state, (to which every other state was bound to submit,) not only to confer the rights of citizenship in other states upon any persons, whom it might admit to such rights within itself, but upon any persons, whom it might allow to become inhabitants within its jurisdiction. But even if an exposition could be given to the term, inhabitants, which would confine the stipulated privileges to citizens alone, the difficulty would be diminished only, and not removed. The very improper power was, under the confederation, still retained in each state of naturalizing aliens in every other state.
§ 1800. The provision in the constitution avoids all this ambiguity. It is plain and simple in its language; and its object is not easily to be mistaken. Connected with the exclusive power of naturalization in the national government, it puts at rest many of the difficulties, which affected the construction of the article of the confederation. It is obvious, that, if the citizens of each state were to be deemed aliens to each other, they could not take, or hold real estate, or other privileges, except as other aliens. The intention of this clause was to confer on them, if one may so say, a general citizenship; and to communicate all the privileges and immunities, which the citizens of the same state would be entitled to under the like circumstances.
The Founders' Constitution
Volume 4, Article 4, Section 2, Clause 1, Document 20
The University of Chicago Press
Story, Joseph. Commentaries on the Constitution of the United States. 3 vols. Boston, 1833.
Easy to print version.