There was another provision which had been already several times applied to this very subject and to other subjects. It was the provision which conferred upon Congress the power to create, or co-operate in creating, new Commonwealths out of the Territories of the United States. This power is expressed in general terms, and in its employment Congress had imposed a number of limitations upon the powers of the new Commonwealths which the Constitution did not impose upon those of the original Commonwealths. Here, then, was a possible way for those seeking the advancement of liberty to effect their purpose. If their interpretation of the Constitution, in regard to the extent of this power, was correct, and they could only command the President and a simple majority in both branches of Congress, they could abolish slavery in every new Commonwealth at the time of its creation, and make the continuance of the free status the perpetual condition of its continued existence as a Commonwealth. It would then be only a question of time when sufficient majorities would be secured for so amending the Constitution of the United States as to expel slavery from the old Commonwealths through the regular forms for constitutional development. It was an attractive scheme, and appeared to provide the means for ridding the country peaceably of its great evil at no very far distant day. It was the last possible means which the Constitution afforded. It was {65} tried in the creation of the Commonwealth of Missouri and it failed. It is this which constitutes the significance of the great movement. The result attained made the abolition of slavery by the United States Government, through legal and peaceable means, an utter impossibility. It contributed, at least, toward making the War of 1861 an historical necessity. As we have seen in the preceding chapter, slaveholding had become established by custom in the vast region known as the Louisiana province, wherever it was inhabited, during the periods when it belonged to Spain and France, and had been permitted to continue after its acquisition by the United States; and that in 1812 this province was divided into one slave-holding Commonwealth, Louisiana, and one slave-holding Territory, Missouri. [Sidenote: Slavery in the Missouri Territory.] From 1812 to 1818 Congress did nothing toward the extinction of slavery in the Missouri Territory, or preventing the free immigration of masters with their slaves into the Territory. Neither had the legislature of the Territory done anything touching these subjects. It may, therefore, be assumed that in the year 1818, the holding of negroes as slaves was legal by custom, if not by positive law, in the whole of the Missouri Territory, so far as it had been settled, and that unless something should thereafter be done, either by the United States Government or by the Territorial government, forbidding it, slavery would be likewise legal wherever the Territory might become settled.