Stephen Arnold Douglas was an American politician and lawyer from Illinois. A senator, he was one of two nominees of the badly split Democratic Party for president in the 1860 presidential election, which was won by Republican candidate Abraham Lincoln. Douglas had previously defeated Lincoln in the 1858 United States Senate election in Illinois, known for the pivotal Lincoln–Douglas debates. He was one of the brokers of the Compromise of 1850 which sought to avert a sectional crisis; to further deal with the volatile issue of extending slavery into the territories, Douglas became the foremost advocate of popular sovereignty, which held that each territory should be allowed to determine whether to permit slavery within its borders. This attempt to address the issue was rejected by both pro-slavery and anti-slavery advocates. Douglas was nicknamed the "Little Giant" because he was short in physical stature but a forceful and dominant figure in politics.

The Democratic Party is one of the two major contemporary political parties in the United States. Since the 1850s, its main political rival has been the Republican Party.