Buchanan had promised in his inaugural address to serve just one term, and with the ongoing national turmoil over slavery and the nature of the Union, there was a deep yearning for fresh leadership within the Democratic Party.

[1] Republican nominee Abraham Lincoln, running on a platform devoted to keeping slavery out of all Western territories, defeated the splintered Democratic Party and Constitutional Union candidate John Bell to win the 1860 election.

[3] The 1856 Democratic National Convention met in June 1856, writing a platform that largely reflected Buchanan's views, including support for the Fugitive Slave Law, an end to anti-slavery agitation, and U.S. "ascendancy in the Gulf of Mexico."

President Pierce and Senator Stephen A. Douglas also sought the nomination, but Buchanan was selected as the Democratic presidential nominee on the seventeenth ballot of the convention.

[6] President-elect Buchanan would also state, "the object of my administration will be to destroy sectional party, North or South, and to restore harmony to the Union under a national and conservative government.

[11][12][13] In 2022 historian David W. Blight argues that the year 1857 was, "the great pivot on the road to disunion...largely because of the Dred Scott case, which stoked the fear, distrust and conspiratorial hatred already common in both the North and the South to new levels of intensity.

"[14] As his inauguration approached, Buchanan sought to establish a harmonious cabinet that would not fall victim to the in-fighting that had plagued Andrew Jackson's top officials.

[27] Two days after Buchanan's inauguration, Chief Justice Taney delivered the Dred Scott decision, which asserted that Congress had no constitutional power to exclude slavery in the territories.

[31] So Buchanan wrote to Grier and successfully prevailed upon him, allowing the majority leverage to issue a broad-ranging decision that transcended the specific circumstances of Scott's case to declare the Missouri Compromise unconstitutional.

Young harassed federal officers and discouraged outsiders from settling in the Salt Lake City area, and in September 1857 the Utah Territorial Militia perpetrated the Mountain Meadows massacre against Arkansans headed for California.

[42] Accepting the wildest rumors and believing the Mormons to be in open rebellion against the United States, Buchanan sent the army in November 1857 to replace Young as governor with the non-Mormon Alfred Cumming.

[28] After Young reacted to the military action by mustering a two-week expedition destroying wagon trains, oxen, and other Army property, Buchanan dispatched Thomas L. Kane as a private agent to negotiate peace.

[47] Upon taking office, Buchanan appointed Robert J. Walker to replace John W. Geary as territorial governor of Kansas, with the mission of reconciling the settler factions and approving a constitution.

Douglas's faction continued to support the doctrine of popular sovereignty, while Buchanan insisted that Democrats respect the Dred Scott decision and its repudiation of federal interference with slavery in the territories.

[64][65] Following the 1858 elections, Senator Jefferson Davis of Mississippi and fellow Southern radicals sought to pass a federal slave code that would protect slavery in the territories, thereby closing the loophole contemplated by Douglas's Freeport Doctrine.

In his December 1859 annual message to Congress, Buchanan characterized the raid as part of an "open war by the North to abolish slavery in the South", and he called for the establishment of a federal slave code.

However, Buchanan's ambitions in Cuba and Mexico were blocked in the House of Representatives, where the anti-slavery forces strenuously opposed any move to acquire new slave territory.

[84] After a long and acrimonious fight, the convention adopted a platform favoring Douglas's conception of popular sovereignty and rejecting a federal slave code.

Douglas preferred Alexander H. Stephens as his running mate, but left the decision to the remaining Southern delegates, who eventually picked former Governor Herschel Johnson of Georgia.

[87] The 1860 Republican National Convention opened with five major candidates: Abraham Lincoln, William Seward, Salmon P. Chase of Ohio, Simon Cameron of Pennsylvania, and Edward Bates of Missouri.

Lincoln's candidacy was boosted by the widely-held view that his reputation for honesty and moderation made him a strong candidate, especially in key Northern swing states like Indiana and Illinois.

[93] Despite Lincoln's presidential victory, Republicans failed to win a majority in the House or Senate, and the Supreme Court membership remained largely the same as it had been when it issued the Dred Scott decision.

A minority of leaders in the Deep South, including Alexander Stephens, opposed secession before Lincoln made a move that would threaten slavery in the Southern states.

With the support of Seward and Lincoln, the Committee of Thirty-Three put forth a resolution to repeal all state personal liberty laws, which were designed to make enforcement of the Fugitive Slave Act more difficult.

[110] Because whichever side that fired the first shot would look like the aggressor and pay a price in the crucial border states, many Southerners hoped to persuade Buchanan to peacefully surrender the forts.

[111] Shortly after Lincoln's election, Buchanan and Secretary of War Floyd had appointed Major Robert Anderson to command Fort Sumter and the other two nearby federal installations.

However, Buchanan failed to ask Major Anderson to provide covering fire for the ship, and it was forced to return North without delivering troops or supplies.

Their policies enraged free-state voters and caused the fatal split in the Democratic Party that resulted in Lincoln's election, which, in turn, triggered disunion.

His many talents, which in a quieter era might have gained for him a place among the great presidents, were quickly overshadowed by the cataclysmic events of civil war and by the towering Abraham Lincoln.

In fact Buchanan's failing during the crisis over the Union was not inactivity, but rather his partiality for the South, a favoritism that bordered on disloyalty in an officer pledged to defend all the United States.