The other effect of the Kansas-Nebraska policy was the rise of a new party formed for the single purpose of opposing it. Anti-Slavery parties had already come into being from time to time in the North, and had at different times exerted a certain influence on elections, but they made little headway because they were composed mainly of extremists, and their aim appeared to moderate men inconsistent with the Constitution. The attack on the time-honoured Missouri Compromise rallied such men to the opposition, for it appeared to them clearly that theirs was now the legal, constitutional, and even conservative side, and that the Slave Power was now making itself responsible for a revolutionary change to its own advantage.
Nor was the change on the whole unjust. The programme to which the South committed itself after the direction of its policy fell from the hands of Calhoun was one which the North could not fail to resent. It involved the tearing up of all the compromises so elaborately devised and so nicely balanced, and it aimed at making Slavery legal certainly in all the new territories and possibly even in the Free States. It was, indeed, argued that this did not involve any aggravating of the evil of Slavery, if it were an evil. The argument will be found very ingeniously stated in the book which Jefferson Davis subsequently wrote--professedly a history of the Southern Confederacy, really rather an _Apologia pro Vita Sua_. Davis argues that since the African Slave Trade was prohibited, there could be no increase in the number of slaves save by the ordinary process of propagation. The opening of Kansas to Slavery would not therefore mean that there would be more slaves. It would merely mean that men already and in any case slaves would be living in Kansas instead of in Tennessee; and, it is further suggested, that the taking of a Negro slave from Tennessee, where Slavery was rooted and normal, to Kansas, where it was new and exceptional, would be a positive advantage to him as giving him a much better chance of emancipation. The argument reads plausibly enough, but it is, like so much of Davis's book, out of touch with realities. Plainly it would make all the difference in the world whether the practice of, say, the Catholic religion were permitted only in Lancashire or were lawful throughout England, and that even though there were no conversions, and the same Catholics who had previously lived in Lancashire lived wherever they chose. The former provision would imply that the British Government disapproved of the Catholic religion, and would tolerate it only where it was obliged to do so. The latter would indicate an attitude of indifference towards it. Those who disapproved of Slavery naturally wished it to remain a sectional thing and objected to its being made national. But the primary feeling was that it was the South that had broken the truce. The Northerners had much justification in saying that their opponents, if not the aggressors in the Civil War, were at least the aggressors in the controversy of which the Civil War was the ultimate outcome.