The 1860 United States presidential election was the 19th quadrennial presidential election, held on Tuesday, November 6, 1860. In a four-way contest, the Republican Party ticket of Abraham Lincoln and Hannibal Hamlin won a national popular plurality, a popular majority in the North where states already had abolished slavery, and a national electoral majority comprising only Northern electoral votes. Lincoln's election thus served as the main catalyst of the states that would become the Confederacy seceding from the Union. This marked the first time that a Republican was elected president. It was also the first presidential election in which both major party candidates were registered in the same home state; the others have been in 1904, 1920, 1940, 1944, and 2016.

A consensus of historians who address the origins of the American Civil War agree that the preservation of the institution of slavery was the principal aim of the eleven Southern states that declared their secession from the United States and united to form the Confederate States of America. However, while historians in the 21st century agree on the centrality of slavery in the conflict, they disagree sharply on which aspects of this conflict were most important, and on the North's reasons for refusing to allow the Southern states to secede. Proponents of the pseudo-historical Lost Cause ideology have denied that slavery was the principal cause of the secession, a view that has been disproven by the overwhelming historical evidence against it, notably the seceding states' own secession documents.