The words of the constitution, "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 may be imposed on such person not exceeding ten dollars for each person,"--clearly show, beyond the possibility of a cavil, that the right to legislate concerning slaves is vested in the general government, and that the convention was fearful that the attempt to exercise it might be made, before the southern states were prepared for any laws upon the subject. The Congress has, in fact, uniformly exercised this right in all its laws for the government of the new states and territories. It prohibited the importation of slaves and their migration into the northwestern territory. The states which ceded the territory south of the Ohio, and east of the Mississippi, were fully aware of this power of Congress; and they ceded it with certain stipulations in favour of the slave holder. Yet even over the states which were formed in this region, has Congress exercised its power, and secured to the slave the right of trial by jury and of the habeas corpus. All these laws were passed without exciting any suspicion that Congress was transcending its powers in thus clogging the constitutions of the new states. They were regarded as decent and becoming in a government founded in justice and freedom, "as extending the fundamental principles of civil and religious liberty." That northwestern territory offered no inducement to the slave holder, or to a slave agriculture. Now, however, the case is altered. A province adapted to the cultivation of cotton and tobacco, and in obtaining which the government made no stipulations in favour of slavery, claims to be elevated to the rank of a state. It is a desirable situation for the planters, and holds out from its situation and fertility a golden prospect. They claim accordingly to be admitted there, with their slaves; and a clamour is raised because the people of the United States are unwilling further to extend slavery--to sacrifice the principles of our republic upon the altar of avarice. The pretence--it scarcely deserves the name of argument--is, that such restriction would be _unconstitutional_, _oppressive_, and _inexpedient_.