as well. In September 1855, Seward led his faction of Whigs into the Republican Party, effectively marking the end of the Whig Party as an independent and significant political force. Thus, the 1856 presidential election became a three-sided contest between Democrats, Know-Nothings, and Republicans. The Know Nothing National Convention nominated Fillmore for president, but disagreements over the party platform's stance on slavery caused many Northern Know-Nothings to abandon the party. Meanwhile, the 1856 Republican National Convention chose John C. Frémont as the party's presidential candidate. The defection of many Northern Know-Nothings, combined with the caning of Charles Sumner and other events that stoked sectional tensions, bolstered Republicans throughout the North. During his campaign, Fillmore minimized the issue of nativism, instead of attempting to use his campaign as a platform for unionism and a revival of the Whig Party. Seeking to rally support from Whigs who had yet to join another party, Fillmore and his allies organized the sparsely-attended 1856 Whig National Convention, which nominated Fillmore for president. Ultimately, Democrat James Buchanan won the election with a majority of the electoral vote and 45 percent of the popular vote; Frémont won most of the remaining electoral votes and took 33 percent of the popular vote, while Fillmore won 22 percent of the popular vote and just eight electoral votes. Fillmore largely retained Taylor and Scott voters in the South, but most former Whigs in the North voted for Frémont rather than Fillmore. Fillmore's American Party collapsed after the 1856 election, and many former Whigs who refused to join the Democratic Party or the Republican Party organized themselves into a loose coalition known as the Opposition Party. For the 1860 presidential election, Senator John J. Crittenden and other unionist conservatives formed the Constitutional Union Party. The party nominated a ticket consisting of John Bell, a long-time Whig senator, and Edward Everett, who had succeeded Daniel Webster as Fillmore's Secretary of State. With the nomination of two former Whigs, many regarded the Constitutional Union Party as a continuation of the Whig Party; one Southern newspaper called the new party the "ghost of the old Whig Party". The party campaigned on preserving the union and took an official non-stance on slavery. The Constitutional Union ticket won a plurality of the vote in three states, but Bell finished in fourth place in the national popular vote behind Republican Abraham Lincoln, Democrat Stephen A. Douglas, and