Bleeding Kansas was the violent time period that occurred when the Kansas territory was being settled and included the fight about whether or not the state should be a slave state or a free state. Bleeding Kansas is also often referred to as Bloody Kansas.
It was in 1854 that the Kansas-Nebraska Act was created and overturned the Missouri Compromise's boundaries. With this Act came the need to determine whether or not the territory would be pro- or antislavery. It was decided that the residents of the state would make the determination. This led to immediate violence as pro-slavery settlers and antislavery settlers started pouring into Kansas in order to help swing the vote in their favor.
These people swarmed the state and started to fight for control. John Brown, the abolitionist, was quick to lead the antislavery people in fighting just before he raided Harpers Ferry. The name "Bleeding Kansas" itself was thought to have been created by the writer Horace Greeley of the "New York Tribune." This civil conflict also led to political polarization. Then on May 21, 1856, the town of Lawrence was looted. As a retaliation, John Brown led an orchestrated murder. Soon armies were involved. The border war did not stop until federal troops were brought in and it was not until 1861 that the violence truly ceased.