John C. Frémont ran for the republicans as a relatively inexperienced politician with few enemies and a national hero status due to his Western Expeditions. The Republicans saw him as their safest bet. His platform said that congress had 'both the right and the imperative duty... to prohibit in the territories those twins relics of barbarism - Polygamy and Slavery.' The polygamy being in relation to the Mormons in Utah.
Millard Fillmore ran for the American Party, but after its split following his nomination he only had influence in the south and at that it was limited. The North-American Party was cornered into supporting Frémont after Nathanial Banks skillfully nominated himself then withdrew in favour of the republican leader leaving the North American Party supporting the Republicans.
The Democrats also went for a 'safe' candidate in the shape of James Buchanan. He had spent 40 years in public service and was from Pennsylvania, perceived to be a battleground state. His platform upheld the 1850 compromise and popular sovereignty.
The campaigning was split between Buchanan and Fillmore in the South, and Buchanan and Frémont in the North. Senator Toombs of Georgia declared that: 'The election of Frémont would be the end of the Union and ought to be'. Which resonated strongly in 1860.
While the republicans had lost the election, which the Democrats becoming more and more segregated they had the largest group of seats in congress 92 of which none were split.