Since the early 1830s, Whigs and Democrats had organized and channeled political conflict in the nation. This party system dampened sectionalism and strengthened the Union. To achieve national political power, the Whigs and Democrats had to retain strength in both North and South. Strong northern and southern wings required that each party compromise and find positions acceptable to both sections.

The Kansas-Nebraska controversy shattered this stabilizing political system. In place of two national parties with bisectional strength, the mid-1850s witnessed the development of one party heavily dominated by one section and another party entirely limited to the other section. Rather than “national” parties, the country had what one critic disdainfully called “geographic” parties, a development that thwarted political compromise between the sections.