Kansas-Nebraska Act

The Kansas-Nebraska Act is an 1854 act of the United States Congress, sponsored by Senator Stephen A. Douglas, that organized the territories of Kansas and Nebraska and allowed the settlers in each to decide by popular sovereignty whether to permit slavery, rather than the question being settled by Congress. In doing so it explicitly repealed the Missouri Compromise line of 1820, which had barred slavery in that part of the former Louisiana Purchase. The act triggered violent conflict between pro-slavery and anti-slavery settlers in Kansas Territory, a period known as Bleeding Kansas, and it split the existing party system, contributing directly to the collapse of the Whig Party and the formation of the new Republican Party in opposition to the act. Historians generally regard it as one of the most consequential steps on the path to the American Civil War.