カンザス・ネブラスカ法
Throughout 1854, Democrats, Whigs, and Free Soilers held state and local conventions, where they denounced the Kansas–Nebraska Act. Many of the larger conventions agreed to nominate a fusion ticket of candidate opposed to the Kansas–Nebraska Act, and some adopted portions of the Free Soil platform from 1848 and 1852. One of these groups met in Ripon, Wisconsin, and agreed to establish a new party known as the Republican Party in the event that the Kansas–Nebraska Act passed. Though many Democrats and Whigs involved in the anti-Nebraska movement still clung to their partisan affiliation, others began to label themselves as Republicans. Another political coalition appeared in the form of the nativist and anti-Catholic Know Nothing movement, which formed the American Party. While the Republican Party almost exclusively appealed to Northerners, the Know Nothings gathered many adherents in both the North and South; some individuals joined both groups even while they remained part of the Whig Party or the Democratic Party.