Actions in Bleeding Kansas
The Kansas-Nebraska Act that created Kansas Territory in 1854 left the question of whether it would be a slave state to elections open to all settlers. Border Ruffians crossed into Kansas and affected the outcomes of several of these key elections by claiming to be settlers and intimidating valid voters. For example, on November 29, 1854, Border Ruffians swayed the vote in favor of a pro-slavery territorial representative to Congress. In the election of March 30, 1855, Border Ruffians were key to electing a pro-slavery Territorial Legislature. Border Ruffians also voted in favor of the Lecompton Constitution (a proposed state constitution, drafted by a constitutional convention of somewhat dubious validity, that allowed slavery). An integral part of these periodic invasions was also outright violence against Free-Staters.
The Border Ruffians at times also engaged in larger battles with Free-State forces. On December 1, 1855, a small army, composed mainly of Border Ruffians, laid siege to Lawrence, Kansas, in the nearly bloodless climax to the "Wakarusa War." On May 21, 1856, Border Ruffians in conjunction with pro-slavery Kansans and officers of the territorial legislature, again attacked Lawrence.
On the other side, anti-slavery Kansas militants (known as Jayhawkers) also committed atrocities against residents of Kansas and Missouri they believed to be unsupportive of their cause, even those who did not own slaves. For example, John Brown, probably the most famous of these militants, led raids where men he believed to be pro-slavery were hacked to death with broadswords.
After Kansas was admitted to the United States as a free state and the Civil War commenced in 1861, hostilities continued between pro-Confederate partisans from Missouri and pro-Union partisans from Kansas. Both sides murdered civilians they suspected of harboring sympathies for the opposition. A number of towns in Missouri, such as Osceola, were sacked by Jayhawkers in the days preceding the Civil War. The movie, The Outlaw Josie Wales portrays the sacking of Osceola.
Abolitionists were referred to as Jayhawkers and is still used as a term of derision by some towards those from Kansas (though Kansans see it as a term of endearment). The term rose when the Jayhawkers "foraged off the enemy". The University of Kansas' mascot, the Jayhawk, is derived from the term, Jayhawkers. Items taken in raids into Missouri were frequently referred to as having been "Jayhawked."