The Kansas-Nebraska Act was a law passed by the United States Congress on May 30, 1854, that organized the territories of Kansas and Nebraska and stipulated that settlers in each territory would decide whether to permit slavery within their borders, a principle known as popular sovereignty. The act effectively repealed the slavery-related provisions of the Missouri Compromise of 1820, which had prohibited slavery in territories north of the 36°30′ parallel. The act's authorship, intent, and consequences remain subjects of historical interpretation; see kansas-nebraska-act-viewpoint-debate for contrasting assessments of the motives behind it.

Historians broadly agree on the basic sequence of events: Senator Stephen A. Douglas of Illinois introduced the bill to organize the Nebraska Territory in January 1854, and the bill was amended to divide the territory into two-Kansas and Nebraska-while incorporating popular sovereignty in place of the Missouri Compromise line. The act passed the Senate on March 3, 1854, the House on May 22, 1854, and was signed into law by President Franklin Pierce on May 30, 1854.

Historians differ on how much weight to give Douglas's stated motives versus other considerations in explaining the act's passage; see kansas-nebraska-act-viewpoint-debate for contrasting assessments. Accounts also differ on how directly the act is linked to subsequent violence in the Kansas Territory and to the realignment of American political parties. Fuller historical background appears at kansas-nebraska-act-history.

The act is frequently discussed in relation to the broader sequence of sectional legislation, including the Compromise of 1850 and the Missouri Compromise, within the wider context of United States of America - 19th Century History.

• Railroad-and-principle viewpoint: Holds that Douglas's primary motivations were to facilitate construction of a transcontinental railroad through Nebraska and to apply popular sovereignty consistently as a democratic principle, with the repeal of the Missouri Compromise line a necessary but secondary consequence. See kansas-nebraska-act-railroad-principle-viewpoint.

• Southern-accommodation viewpoint: Holds that Douglas and northern supporters primarily intended to secure southern congressional support, whether for the railroad route, party unity, or personal political ambition, and that popular sovereignty was adopted chiefly as a means to that end rather than as a guiding principle. See kansas-nebraska-act-southern-accommodation-viewpoint.

• Slave-power-conspiracy viewpoint: Holds, as many contemporary northern critics argued, that the act represented a deliberate scheme by pro-slavery interests to extend slavery into territory previously closed to it, in violation of the spirit and letter of prior compromises. See kansas-nebraska-act-slave-power-viewpoint.

• States'-rights/popular-sovereignty viewpoint: Holds, as many contemporary southern and Democratic defenders argued, that the act correctly extended the principle of local self-government to the territories and that no territory or its prospective settlers should be bound in advance by Congress on the question of slavery. See kansas-nebraska-act-popular-sovereignty-viewpoint.

• Catalyst-for-realignment viewpoint: Holds that the act's primary historical significance lies in its role in destroying the Whig Party, fracturing the Democratic Party along sectional lines, and giving rise to the Republican Party, more than in its direct legal or demographic effects on Kansas and Nebraska. See kansas-nebraska-act-realignment-viewpoint.

• The act's implementation in the Kansas Territory produced sustained, often violent conflict between pro-slavery and free-state settlers and competing territorial governments, an episode commonly known as “Bleeding Kansas.” See kansas-nebraska-act-bleeding-kansas-controversy.

• Disputed elections and rival constitutional conventions in Kansas, including the Lecompton Constitution, generated a prolonged controversy over which territorial government held legitimate authority. See kansas-nebraska-act-lecompton-constitution-controversy.

• History: kansas-nebraska-act-history
• Viewpoint Debate: kansas-nebraska-act-viewpoint-debate
• Controversy: kansas-nebraska-act-bleeding-kansas-controversy, kansas-nebraska-act-lecompton-constitution-controversy
• Related Main Topics: Missouri Compromise, Compromise of 1850, United States of America - 19th Century History, United States of America - History

1. Michael J. Birkner, ed., *James Buchanan and the Political Crisis of the 1850s* (Selinsgrove, PA: Susquehanna University Press, 1996).
2. David M. Potter, *The Impending Crisis, 1848-1861*, completed and ed. Don E. Fehrenbacher (New York: Harper & Row, 1976).
3. Nicole Etcheson, *Bleeding Kansas: Contested Liberty in the Civil War Era* (Lawrence: University Press of Kansas, 2004).
4. Robert W. Johannsen, *Stephen A. Douglas* (New York: Oxford University Press, 1973).
5. James A. Rawley, *Race and Politics: “Bleeding Kansas” and the Coming of the Civil War* (Philadelphia: Lippincott, 1969).