Stephen A. Douglas (1813 - 1861) was an American politician and lawyer, best known for his role in the debates with Abraham Lincoln during the Illinois Senate race of 1858 and for his support of popular sovereignty regarding the expansion of slavery in the United States. Born in Vermont on April 23, 1813, Douglas became a prominent figure in Illinois politics and was elected to the U.S. Senate in 1847. 

Douglas is most famous for his involvement in the Kansas-Nebraska Act of 1854, which allowed settlers in those territories to decide for themselves whether to permit slavery, a concept known as popular sovereignty. This act effectively repealed the Missouri Compromise and heightened tensions over slavery in the United States. He also played a central role in the Compromise of 1850, which attempted to ease sectional divisions.

In the 1860 presidential election, Douglas was the nominee for the Northern Democratic Party, but he lost to Abraham Lincoln. His political career and life were cut short by his death in 1861, but he is remembered as a leading figure in the years leading up to the Civil War.