Candidates opposed to the Democratic Party won widely in the Northern United States through November 1854.

Congress had passed the Kansas–Nebraska Act in May 1854 after aggressive sponsorship by the Pierce Administration and Democrats led by Senator Stephen Douglas, including radical pro-slavery legislators.

With widely foreseen risks and immediately negative results, the Act discredited the Democratic Party, fueling new partisan and sectional rancor.

The Act repealed the 1820 Missouri Compromise and triggered the violent Bleeding Kansas conflict, creating uncertainty on the Western frontier by abruptly making slavery potentially legal in territories originally comprising the northern portion of the Louisiana Purchase.

After two months and 133 ballots, American Party representative Nathaniel Banks of Massachusetts, also a Free Soiler, defeated Democrat William Aiken of South Carolina by plurality, 103–100.