The abolition of the slave trade by Congress, in 1808, is another illustration of the competency of legislative power to abolish slavery.  The African slave trade has become such a mere technic, in common parlance, that the fact of its being proper slavery is overlooked.  The buying and selling, the transportation, and the horrors of the middle passage, were mere incidents of the slavery in which the victims were held.  Let things be called by their own names.  When Congress abolished the African slave trade, it abolished SLAVERY—­supreme slavery—­power frantic with license, trampling a whole hemisphere scathed with its fires, and running down with blood.  True, Congress did not, in the abolition of the slave trade, abolish all the slavery within its jurisdiction, but it did abolish all the slavery in one part of its jurisdiction.  What has rifled it of power to abolish slavery in another part of its jurisdiction, especially in that part where it has “exclusive legislation in all cases whatsoever?”

8.  THE CONSTITUTION OF THE UNITED STATES RECOGNISES THIS POWER BY THE MOST CONCLUSIVE IMPLICATION.  In Art. 1, sec. 3, clause 1, it prohibits the abolition of the slave trade previous to 1808:  thus implying the power of Congress to do it at once, but for the restriction; and its power to do it unconditionally, when that restriction ceased.  Again; In Art. 4, sec. 2, “No person held to service or labor in one state under the laws thereof, escaping into another, shall in consequence of any law or regulation therein, be discharged from said service or labor.”  This clause was inserted, as all admit, to prevent the runaway slave from being emancipated by the laws of the free states.  If these laws had no power to emancipate, why this constitutional guard to prevent it?

The insertion of the clause, was the testimony of the eminent jurists that framed the Constitution, to the existence of the power, and their public proclamation, that the abolition of slavery was within the appropriate sphere of legislation.  The right of the owner to that which is rightfully property, is founded on a principle of universal law, and is recognised and protected by all civilized nations; property in slaves is, by general consent, an exception; hence slaveholders insisted upon the insertion of this clause in the United States Constitution, that they might secure by an express provision, that from which protection is withheld, by the acknowledged principles of universal law.[A] By demanding this provision, slaveholders consented that their slaves should not be recognised as property by the United States Constitution, and hence they found their claim, on the fact of their being “persons, and held to service.”