The year of 1852 was the beginning of the end for the Whigs. The deaths of Henry Clay and Daniel Webster that year severely weakened the party. The Compromise of 1850 fractured the Whigs along pro- and anti-slavery lines, with the anti-slavery faction having enough power to deny Fillmore the party's nomination in 1852. 1852's Whig Party convention in New York City saw the historic meeting between Alvan E. Bovay and The New York Tribune's Horace Greeley, a meeting which led to correspondence between the men as the early Republican Party meetings in 1854 began to take place. Attempting to repeat their earlier successes, the Whigs nominated popular General Winfield Scott, who lost decisively to the Democrats' Franklin Pierce. The Democrats won the election by a large margin: Pierce won 27 of the 31 states including Scott's home state of Virginia. Whig Representative Lewis D. Campbell of Ohio was particularly distraught by the defeat, exclaiming, "We are slain. The party is dead--dead--dead!" Increasingly politicians realized that the party was a loser. Abraham Lincoln, its Illinois leader, for example, ceased his Whig activities and attended to his law business.
In 1854, the Kansas-Nebraska Act, which opened the new territories to slavery, was passed. Southern Whigs generally supported the Act while Northern Whigs remained strongly opposed. Most remaining Northern Whigs, like Lincoln, joined the new Republican Party and strongly attacked the Act, appealing to widespread northern outrage over the repeal of the Missouri Compromise. Other Whigs joined the Know-Nothing Party, attracted by its nativist crusades against so-called "corrupt" Irish and German immigrants. In the South, the Whig party vanished, but as Thomas Alexander has shown, Whiggism as a modernizing policy orientation persisted for decades.Historians estimate that, in the South in 1856, Fillmore retained 86 percent of the 1852 Whig voters. He won only 13% of the northern vote, though that was just enough to tip Pennsylvania out of the Republican column. The future in the North, most observers thought at the time, was Republican. No one saw any prospects for the shrunken old party, and after 1856 there was virtually no Whig organization left anywhere. Some Whigs and others adopted the mantle of the "Opposition Party" for several years and had some success.
In 1860, many former Whigs who had not joined the Republicans regrouped as the Constitutional Union Party, which nominated only a national ticket; it had considerable strength in the border states, which feared the onset of civil war. John Bell finished third in the electoral college. During the latter part of the war and Reconstruction, some former Whigs tried to regroup in the South, calling themselves "Conservatives", and hoping to reconnect with ex-Whigs in the North. They were soon swallowed up by the Democratic Party in the South, but continued to promote modernization policies such as railroad building and public schools.
In today's discourse in American politics, the Whig Party is usually mentioned in the context of a political party losing its followers and reason for being, often exemplified by the phrase "going the way of the Whigs."