The special equivalent which the Northern States received for these concessions was in the establishment of what is called “the commercial power,” or the power of Congress to regulate for the whole country the trade with foreign nations and between the States; a power which it was foreseen was to be one of vast importance, which was one of the chief objects for which the new Union was to be formed, and which proved in the event to be all, and more than all, that had been anticipated for it. Viewed in the light of mutual stipulations, these so-called “compromises” between the two sections were laid at the basis of the Constitution, forming a settlement fixed in the supreme law of the land, and therefore determinate and final. Contemporaneously with the formation of the Constitution, and before its adoption, the Congress of the Confederation was engaged in framing an ordinance for the government of the Northwestern Territory, a region of country north and west of the Ohio, which Virginia and other States had ceded to the United States during the war of the revolution. From this region the ordinance excluded slavery by an agreement made in that Congress between the Northern and the Southern States. The Constitution did not take notice of this Northwestern Territory by its specific designation, but it was made to embrace a provision empowering the new Congress “to make all needful rules and regulations respecting the territory and all other property of the United States,” and also a provision for the admission into the Union of new States, to be formed out of any territory belonging to the United States. For a long period after the adoption of the Constitution, these two provisions, taken together, were regarded as establishing a plenary power of legislation over the internal condition of any territory that might in any way become the property of the United States, while it remained subject to the exclusive jurisdiction of Congress, and down to the time when its inhabitants were to be permitted to form themselves into a State that was to be admitted into the Union upon an equality with all the other States. Under this process, between the years 1792 and 1820, nine new States were admitted into the Union; five of them with slavery and four of them without it. Of these, three were formed out of parts of the Northwestern Territory, and they therefore derived their character as free States from the admitted force of the ordinance of 1787; while the others were not within the scope of that ordinance, but derived their character from the legislative authority of Congress under the Constitution.