Wilmot Proviso in the context of "Stephen A. Douglas"

Stephen Arnold Douglas (né Douglass; April 23, 1813 – June 3, 1861) was an American politician and lawyer from Illinois. As a U.S. senator, he was one of two nominees of the badly split Democratic Party to run 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. Earlier, Douglas 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. Standing 5 feet 4 inches (1.63 m) tall, Douglas was nicknamed the "Little Giant" because he was short in physical stature but a forceful and dominant figure in politics.

Born in Brandon, Vermont, Douglas migrated to Jacksonville, Illinois, in 1833 to establish a legal practice. He experienced early success in politics as a member of the newly formed Democratic Party, serving in the Illinois House of Representatives and various other positions. He was appointed to the Supreme Court of Illinois in 1841. In 1843, he was elected to the U.S. House of Representatives and therefore resigned from the Supreme Court of Illinois. Douglas became an ally of President James K. Polk and favored the annexation of Texas and the Mexican–American War. He was one of four Northern Democrats in the House to vote against the Wilmot Proviso, which would have banned slavery in any territory acquired from Mexico.