The middle years of the 1850s saw a profound transformation in American politics. As 1854 opened, sectional animosities were at a low point and the two-party system pitted, as it had for twenty years, Democrat against Whig, with each party able to recruit from each side of the Mason–Dixon line. By the time the results of the presidential election of 1856 were known, a transformation had occurred. One of the two parties, the Whigs, had ceased to exist, the other, the Democrats, had suffered an extraordinary reversal of fortune across almost the entire North, and sectional tensions were greater than at any time in the nation’s entire history. As if all this were not enough, by the end of 1856 the temperance cause, once so full of disruptive potential, was in headlong retreat while the Know Nothings had, as a political force, experienced a meteoric rise and an equally spectacular fall. Finally a new party, the Republicans, had come into existence and had done remarkably well in the presidential election that had just been held. An observer could have been forgiven for wondering how such dramatic and bewildering changes could have taken place in so short a period of time.

These were years of political confusion and even chaos. In 1854 several processes converged. First there was a general dissatisfaction with party politics; Whig and Democrat seemed to have little to argue about. The result was to prepare the ground for other issues, ones with which the party system might not be able to cope. Second some of those new issues, which historians often refer to as “ethnocultural”, were themselves acquiring new vitality. The temperance crusade was having its impact upon politicians and voters alike; the Know Nothing movement would play a still more dramatic role. Both would inflict damage on the second party system. Finally, and most important, events in Kansas would bring sectional issues, those that pitted North against South, bubbling to the very top of the political agenda. These were the issues that would ultimately destroy the second party system and then, within a few short years, the unity of the nation.