https://caselaw.findlaw.com/us-supreme-court/48/283.html
Justice McKINLEY:
"I have examined the opinions of Mr. Justice McLean and Mr. Justice Catron, and concur in the whole reasoning upon the main question, but wish to add, succinctly, my own views upon a single provision of the Constitution.
The first clause of the ninth section and first article of the [48 U.S. 283, 453] Constitution provides, that 'the migration or importation of such persons as any of the States now existing shall think proper to admit shall not be prohibited by the Congress prior to the year 1808; but a tax or duty may be imposed on such importation, not exceeding ten dollars for each person.'
On the last argument of this cause, no reference was made to this clause of the Constitution; nor have I ever heard a full and satisfactory argument on the subject. Yet on a full examination of this clause, connected with other provisions of the Constitution, it has had a controlling influence on my mind in the determination of the case before us. Some of my brethren have insisted that the clause here quoted applies exclusively to the importation of slaves. If the phrase, "the migration or importation of such persons," was intended by the Convention to mean slaves only, why, in the assertion of the taxing power, did they, in the same clause, separate migration from importation, and use the following language: — "But a tax or duty may be imposed on such importation, not exceeding ten dollars for each person"?
All will admit, that, if the word migration were excluded from the clause, it would apply to slaves only. An unsuccessful attempt was made in the Convention to amend this clause by striking out the word migration, and thereby to make it apply to slaves exclusively. In the face of this fact, the debates in the Convention, certain numbers of the Federalist, together with Mr. Madison's report to the legislature of Virginia in 1799, — eleven years after the adoption of the Constitution, — are relied on to prove that the words migration and importation are synonymes, within the true intent and meaning of this clause. The acknowledged accuracy of language and clearness of diction in the Constitution would seem to forbid the imputation of so gross an error to the distinguished authors of that instrument.
I have been unable to find any thing in the debates of the Convention, in the Federalist, or the report of Mr. Madison, inconsistent with the construction here given. Were they, however, directly opposed to it, they could not, by any known rule of construction, control or modify the plain and unambiguous language of the clause in question. The conclusion, to my mind, is therefore irresistible, that there are two separate and distinct classes of persons intended to be provided for by this clause.
Although they are both subjects of commerce, the latter class only is the subject of trade and importation. The slaves are not immigrants, and had no exercise of volition in their transportation from Africa to the United States.
The owner was bound to enter them at the custom-house as 454*454 any other article of commerce or importation, and to pay the duty imposed by law, whilst the persons of the first class, although subjects of commerce, had the free exercise of volition, and could remove at pleasure from one place to another; and when they determined to migrate or remove from any European government to the United States, they voluntarily dissolved the bond of allegiance to their sovereign, with the intention to contract a temporary or permanent allegiance to the government of the United States, and if transported in an American ship, that allegiance commenced the moment they got on board. They were subject to, and protected by, the laws of the United States, to the end of their voyage.
Having thus shown that there are two separate and distinct classes included in, and provided for by, the clause of the Constitution referred to, the question arises, how far the persons of the first class are protected, by the Constitution and laws of the United States, from the operation of the statute of New York now under consideration. The power was conferred on Congress to prohibit migration and importation of such persons into all the new States, from and after the time of their admission into the Union, because the exemption from the prohibition of Congress was confined exclusively to the States then existing, and left the power to operate upon all the new States admitted into the Union prior to 1808. Four new States having been thus admitted within that time, it follows, beyond controversy, that the power of Congress over the whole subject of migration and importation was complete throughout the United States after 1808.
The power to prohibit the admission of "all such persons" includes, necessarily, the power to admit them on such conditions as Congress may think proper to impose; and therefore, as a condition, Congress has the unlimited power of taxing them. If this reasoning be correct, the whole power over the subject belongs exclusively to Congress, and connects itself indissolubly with the power to regulate commerce with foreign nations. How far, then, are these immigrants protected, upon their arrival in the United States, against the power of State statutes? The ship, the cargo, the master, the crew, and the passengers are all under the protection of the laws of the United States, to the final termination of the voyage; and the passengers have a right to be landed and go on shore, under the protection and subject to these laws only, except so far as they may be subject to the quarantine laws of the place where they are landed; which laws are not drawn in question in this controversy. The great question here is, Where does the power of the United States over this subject end, and where does the 455*455 State power begin? This is, perhaps, one of the most perplexing questions ever submitted to the consideration of this court...."