[92] H. Adams, vol. ix., p. 115. _Annals of Congress_, 1815-1816, p. 1272. [93] H. Adams, vol. ix., p. 116. [94] H. Adams, vol. ix., p. 148. [95] See H. Adams, vol. ix., pp. 149 to 153, for debate and Calhoun’s views. In 1819 and 1820 came the admission of Missouri and the struggle over the extension or restriction of slavery. The Southern statesmen feared that the South was losing its relative importance in the Union. Even those of Virginia, who had formerly been opposed to slavery, now took the opposite view, and the Legislature of that State passed resolutions for the admission of Missouri with slavery. The increase in the production of cotton had made the raising of slaves profitable. The controversy was settled by the bill called the Missouri Compromise, admitting Missouri with slavery, and excluding slavery from all the rest of the country west of that State and north of 36° 30′, the southern boundary of Missouri. This was the first important controversy dividing the States geographically. It was the division that Mason, Madison, and others foresaw in the convention that made the Constitution; not a combination of the great States against the small, but geographical, between the South and the North, the planting and commercial States, and, underlying this and more potent, the institution of slavery repugnant to the North and existing only in the South. It was this difference of interest between the two sections that brought Calhoun to a change of opinion on the great industrial, commercial, and moral questions that had arisen. His convictions followed what he wished to believe: not an unusual temperament. From a protectionist he became the zealous advocate of extreme free trade, from a nationalist to the belief that the Union was nothing but a league any State could break at its will, from holding slavery to be a moral evil to the support of it as a divine institution. In 1837, after the nullification controversy, when he introduced resolutions in the Senate as to slavery, he said: “This question has produced one happy effect, at least it has compelled us of the South to look into the nature and character of this great institution (slavery), and to correct many false impressions that even we had entertained in relation to it. Many in the South once believed that it was a moral and political evil. That folly and delusion are gone. We see it now in its true light, and regard it as the most safe and stable basis for free institutions in the world. It is impossible with us that the conflict take place between labor and capital.”