There are but four provisions of the Constitution wherein the subject of slavery is alluded to, viz: Art. 1, sec. 2; art. 1, sec. 9; art. 4, sec. 2; and art. 5.
It is plain from these provisions—
1st—That the slaveholding States are entitled under the Constitution to representation in the national legislature upon three-fifths of their slaves, so long as slavery exists in those States; and they are subject to direct taxation accordingly.
2d—That the right under State laws to import slaves into the then existing States, was guaranteed for twenty years, or until 1808, and the guarded concession of the right involved the converse, that after 1808 the foreign slave trade was to be prohibited by Congress, for the reason already assigned, and any attempt by Congress now to open the African slave trade, would be as direct a moral violation of this compromise of the Constitution as if the Congress were to attempt directly to abolish slavery in any State.
3d—It is equally plain that the right of slave owners to recover fugitive slaves, escaping from the State where they are held, under the laws thereof, into another, is guaranteed.
The Federal Constitution so far as relates to the subject of slavery within the United States, involves the three propositions stated and nothing more, and there is nothing in these in the least degree expressing or implying a right in Congress to abolish or establish slavery in any State or territory of the Union. On the contrary, the whole tenor of the Constitution is, slavery is the creation of local law, and Congress is to let it alone.
Now as to the question of slavery in the territories and the power and policy of the Federal government concerning it there.
The power to acquire territory for the purpose of colonization or the creation of States was not expressly granted to the Federal government, either by the Articles of Confederation or by the Constitution, but it has been largely exercised under both systems of government. The acts of the government of the Confederation in accepting cessions from several of the States of unoccupied territory, claimed by them in the west, and organizing territorial governments therein, were declared in 1788, by as high authority as James Madison, to be "without the least color of constitutional authority." But as has been the case with many other usurpations of the Federal and other governments, the value of the ends to be attained seems to have justified the usurpation in the public mind.
The territory acquired by Congress under the Confederation was territory which was claimed by or belonged to certain of the original States. The territory acquired under the Constitution has been foreign territory. Louisiana was acquired in 1803 from France, Florida in 1819 from Spain, Texas in 1846 by annexation as a State, a portion of Oregon in 1846 by a boundary treaty, and a large territory including New Mexico, Utah and California by treaty with Mexico in 1848.
The purchase of Louisiana was a measure of Mr. Jefferson, but so serious were his doubts as to the constitutionality of the purchase, that he advised an amendment of the Constitution, but no such amendment was attempted, and the purchase was finally made and acquiesced in, upon the principle that the end justified the means. It seems now, however, to be generally conceded that the power of the Federal government to acquire territory, exists by implications either in the treaty making power or in the power to admit new States. In view of the only legitimate end and purpose of all such acquisitions, it is natural to look upon the power of acquiring as an incident of the power to admit new States.