In the mid-19th century many people in the United States disagreed about the issue of slavery. The Kansas-Nebraska Act of 1854 made slavery once again possible in territories where it had been outlawed since 1820. The result was violent conflict in Kansas between proslavery and antislavery activists, setting the stage for the American Civil War.

The act

The Kansas-Nebraska Act organized the lands west of Missouri and Iowa into two territories that were expected one day to become states. The act allowed the territories' own residents to decide whether or not to allow slavery within their borders. The Missouri Compromise of 1820 had stated that no new state north of the southern boundary of Missouri would be allowed to have slaves. Since both Kansas and Nebraska would be in this range, the new act seemed to be changing the law.

The rush to Kansas

Many Northerners protested the act. Nebraska stayed relatively calm, but Kansas soon became a battleground between proslavery and antislavery settlers who arrived in large numbers. In 1855, the first territorial election went to the proslavery side, helped by “raiders” from the nearby slaveholding state of Missouri. Slavery was promptly legalized in the territory.

Opponents of slavery known as abolitionists refused to accept the vote. Aided by groups in the Northern and Eastern states, they held their own election and set up their own government in the town of Lawrence.

“Bleeding Kansas”

On May 21, 1856, much of Lawrence was destroyed by a proslavery group. Three days later the abolitionist John Brown and his followers struck back and killed five men in what came to be called the Pottawatomie Massacre. Along the Missouri border, the two sides continued to fight battles, capture towns, and take prisoners. Elsewhere in the United States, the area was known as “Bleeding Kansas.”

President Franklin Pierce, who had supported the Kansas-Nebraska Act, struggled to restore order while staying generally on the side of the Southerners. Eventually he sent federal troops into the territory. A new election was then called and again the proslavery party won by using unfair tactics. Their proposed constitution was rejected by the U.S. Congress. Kansas had to remain a territory.

Eventually the free-state settlers became more numerous, and finally the South gave up the attempt to make Kansas a slave state. Kansas was admitted to the Union as a free state on January 29, 1861, just before the start of the Civil War. The disorder that followed from the Kansas-Nebraska Act showed how deeply the United States was divided by the issue of slavery.