1860 United States presidential election

Presidential elections were held in the United States on November 6, 1860. The Republican Party ticket of Abraham Lincoln and Hannibal Hamlin emerged victorious in a four-way race. With an electoral majority composed only of Northern states that had already abolished slavery, and minimal support in the Democratic-dominated Southern slave states, Lincoln's election as the first Republican president thus served as the main catalyst for Southern secession and consequently the American Civil War.

The United States had become sectionally divided during the 1850s, primarily over extending slavery into the western territories. Furthermore, uncompromising pro-slavery elements clashed with those in favor of compromise; this created four main parties in the 1860 election, each with their own presidential candidate. The incumbent president, James Buchanan, like his predecessor, Franklin Pierce, was a Northern Democrat with Southern sympathies. Buchanan also adamantly promised not to seek reelection.

From the mid-1850s, the anti-slavery Republican Party became a major political force, driven by Northern voter opposition to the Kansas–Nebraska Act and the Supreme Court's 1857 decision in Dred Scott v. Sandford. In the 1856 election, the Republican Party had replaced the defunct Whig Party as the major opposition to the Democrats. The 1860 Republican National Convention in Chicago nominated Abraham Lincoln, a former one-term Whig Representative from Illinois. Its platform promised not to interfere with slavery in the South but opposed extension of slavery into the territories.

A group of former Whigs and Know Nothings formed the Constitutional Union Party, which sought to avoid disunion by resolving divisions over slavery with some new compromise. The 1860 Constitutional Union Convention, which hoped to avoid the slavery issue entirely, put forward a slate led by former Tennessee Senator John Bell running for president.

After a walkout of Southern delegates led by William L. Yancey, the 1860 Democratic National Convention in Charleston, South Carolina adjourned without agreeing on a nominee, but a second convention two months later in Baltimore, Maryland nominated Illinois Senator Stephen A. Douglas. Douglas's support for the concept of popular sovereignty, which called for each territory's settlers to decide locally on the status of slavery, alienated many radical pro-slavery Southern Democrats, who wanted the territories and perhaps other lands, to be open to slavery. With President Buchanan's support, Southern Democrats held their own convention, nominating Vice President John C. Breckinridge of Kentucky to run for president.

While Lincoln and Douglas supporters split the northern vote, Bell and Breckinridge vied for victory in the southern states. When the votes were counted, Lincoln received a national majority in the electoral college, but all his electoral college votes came from Northern states. Lincoln won a popular majority in the North, and a nationwide plurality of the popular vote, but his national share of 39.7 percent of the popular vote is to date the lowest for any winner except for 1824 (which was decided by a contingent election, a special vote held in the U.S. House of Representatives). Lincoln received no votes in 10 Southern states because the Republican Party was absent in those states (parties rather than states printed ballots in that era).

Douglas won the second-highest popular vote total nationally, but only twelve electoral college votes: nine in Missouri (a slave state) and three in New Jersey (a free state). Douglas was the only candidate in the 1860 election to win electoral votes in both free and slave states. In the South, Bell won three border states' electoral college seats (Kentucky, Tennessee, and Virginia), and Breckinridge swept the remaining nine, plus Maryland and Delaware. Lincoln's election motivated seven Southern states, all having voted for Breckinridge, to secede before Lincoln's inauguration in March. The American Civil War began less than two months after the inauguration, with the Battle of Fort Sumter; afterwards four further states seceded. Lincoln went on to win re-election in the 1864 United States presidential election, when voting excluded the Confederate states. The 1860 election was the first of six consecutive Republican victories.