Bleeding Kansas describes the period of repeated outbreaks of violent guerrilla warfare between pro-slavery and anti-slavery forces following the creation of the new territory of Kansas in 1854. In all, some 55 people were killed between 1855 and 1859. The struggle intensified the ongoing debate over the future of slavery in the United States and served as a key precursor to the Civil War.

Passage of the Kansas-Nebraska Act

By early 1854, with the United States expanding rapidly westward, Congress had begun debating a proposed bill to organize the former Louisiana Purchase lands then known as the Nebraska Territory. To get crucial southern votes for the bill, Senator Stephen Douglas of Illinois proposed an amendment that effectively repealed the Missouri Compromise, which had outlawed the extension of slavery north of the 36º 30’ parallel (Missouri’s southern border) except in Missouri itself.

Passed over fierce opposition in Congress and signed into law in 1854, the Kansas-Nebraska Act created the territories of Kansas and Nebraska and gave each the right to decide whether or not to permit slavery when it joined the Union. Douglas believed that popular sovereignty, as this idea was known, would resolve the ongoing sectional debate between North and South over slavery’s extension into the territories.

The Kansas-Nebraska Act divided Douglas’ Democratic Party and inspired the formation of the Republican Party, which opposed extending slavery into new territory. While Nebraska was so far north that it was virtually guaranteed to become a free state, Kansas bordered the slave state of Missouri. Over the next seven years, Kansas became a battleground over the future of slavery in the United States. 

Struggle Over Elections

In New England, a group of abolitionists formed the Emigrant Aid Company, which sent anti-slavery settlers to Kansas to ensure it would become a free territory. On the other side, thousands of pro-slavery Missourians flooded into the new territory to illegally vote in Kansas’ first territorial election in November 1854. Pro-slavery candidate John Whitfield easily defeated two Free Soil candidates to become the territory’s delegate to Congress, with only half the ballots cast by registered voters.

In March 1855, when elections took place for the first territorial legislature, thousands of heavily armed “border ruffians” showed up in Kansas again. Through illegal votes and intimidation of anti-slavery voters, they ensured the election of a slate of pro-slavery legislators. 

Northerners and other anti-slavery settlers refused to accept this government and set up their own. Some of these Free Staters, known as “jayhawkers,” armed themselves in preparation for clashes with pro-slavery forces. As tensions increased within the territory, President Franklin Pierce recognized the pro-slavery legislature as the only legitimate government of Kansas. 

Did you know? During the Civil War, Kansas suffered the highest rate of fatal casualties of any Union state, largely because of its great internal divisions over the issue of slavery.

John Brown Responds to Violence in Lawrence

Sporadic outbursts of violence occurred between pro-and anti-slavery forces in late 1855 and early 1856. In a sharp escalation of that violence, a pro-slavery group stormed the Free State stronghold of Lawrence on May 21, 1856, destroying printing presses, looting homes and stores and setting fire to a hotel.

In response to the “Sack of Lawrence,” as it became known, the abolitionist John Brown marched through Pottawatomie Valley in Kansas territory on May 24 along with seven men, including four of his sons. Determined to confront pro-slavery settlers, the group dragged five men from their homes along Pottawatomie Creek and brutally killed them.

Despite the visibility of the violence in Kansas, relatively few of the settlers in the new territory were deeply invested in the conflict over slavery. Many of those listed on the pro-slavery side were poor farmers who didn’t even enslave people, while few anti-slavery settlers were champions of Black rights. Both groups simply wanted land for themselves and their families, but were caught up in the ongoing battle that was tearing the nation apart.

'Bleeding Kansas' Draws National Attention

The upheaval in Kansas captured the attention of the entire nation and even spread to Congress. Two days before Brown’s attack in Pottawatomie, Representative Preston Brooks of South Carolina beat Senator Charles Sumner of Massachusetts with his cane on the Senate floor in retaliation for Sumner’s angry speech denouncing supporters of slavery in Kansas (including Brooks’ cousin, Senator Andrew Butler of South Carolina).

In July 1856, pro-slavery forces suppressed a meeting of the Free State government in Topeka, another anti-slavery stronghold. Brown again retaliated, leading his supporters in guerrilla attacks at Black Jack and Osawatomie. That fall, newly appointed territorial governor John Geary ordered armed settlers to disperse, and the violence waned.

In late 1857, Free Staters boycotted the vote to send delegates to a constitutional convention at Lecompton, citing illegal pro-slavery influences on the election. Seeking to quickly resolve the issue of Kansas statehood, President James Buchanan pushed Congress to accept the Lecompton Constitution, despite overwhelming opposition from Douglas and others who saw it as an illegal violation of popular sovereignty. 

As a compromise, Congress sent the Lecompton Constitution back to Kansas for another vote in August 1858; this time Free Staters voted, and the constitution was rejected. 

Impact of Bleeding Kansas

Though attention on Kansas had waned after 1856, sporadic violence continued, including the murder of a group of Free Staters along the Marais des Cygnes River in May 1858 and the temporary return of Brown, who led a raid to liberate a group of enslaved people in the winter of 1858-59. Brown’s role in the violence in Kansas helped him raise money for his raid on Harpers Ferry in Virginia in 1859. The raid failed, and Brown was executed, becoming a martyr to the abolitionist cause.

The unsettled situation in Kansas was still a matter of heated controversy during the 1858 Senate race in Illinois, when the former one-term congressman Abraham Lincoln, now a Republican, challenged Douglas for his Senate seat. Lincoln lost that race but his eloquent performance in their series of debates helped revive his political career and earn him a national reputation by 1860.

Though Kansas adopted a free state constitution in a convention at Wyandotte in 1859, pro-slavery forces in the Senate refused to let the territory enter the Union as a free state. Only after the Confederate states seceded in the wake of Lincoln’s election in 1860 did Congress approve the Wyandotte Constitution. Kansas entered the Union in January 1861, barely three months before the Civil War began.

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Bleeding Kansas. American Battlefield Trust.
Ross Drake, “The Law That Ripped America in Two.” Smithsonian, May 2004.
Nicole Etcheson, “Bleeding Kansas: From the Kansas-Nebraska Act to Harpers Ferry.” Civil War on the Western Border: The Missouri-Kansas Conflict, 1854-1865. Kansas City Public Library.
Eric Foner, The Fiery Trial: Abraham Lincoln and American Slavery (W.W. Norton, 2010)