The Kansas–Nebraska Act of 1854 (10 Stat. 277) was a territorial organic act that created the territories of Kansas and Nebraska. It was drafted by Democratic Senator Stephen A. Douglas, passed by the 33rd United States Congress, and signed into law by President Franklin Pierce. Douglas introduced the bill intending to open up new lands to develop and facilitate the construction of a transcontinental railroad. However, the Kansas–Nebraska Act effectively repealed the Missouri Compromise of 1820, stoking national tensions over slavery and contributing to a series of armed conflicts known as "Bleeding Kansas".
The United States had acquired vast amounts of land in the 1803 Louisiana Purchase, and since the 1840s, Douglas had sought to establish a territorial government in a portion of the Louisiana Purchase that was still unorganized. Douglas's efforts were stymied by Senator David Rice Atchison of Missouri and other Southern leaders who refused to allow the creation of territories that banned slavery; slavery would have been banned because the Missouri Compromise outlawed slavery in the territory north of latitude 36° 30′ north (except for Missouri). To win the support of Southerners like Atchison, Pierce and Douglas agreed to back the repeal of the Missouri Compromise, with the status of slavery instead decided based on "popular sovereignty". Under popular sovereignty, the citizens of each territory, rather than Congress, would determine whether slavery would be allowed.
