Answer:
The event that started "Bleeding Kansas" was the passing of the Kansas-Nebraska Act of 1854.
Explanation:
At the heart of the conflict between pro and anti slavery sides was the question of whether Kansas, until then a single Territory, would enter the Union as a "free" state or, on the contrary, as a slave state. In this sense, Bleeding Kansas was a proxy dispute between Northerners and Southerners around the issue of slavery on the territory of the United States.
The United States Congress had long struggled to maintain a delicate balance between slavers and abolitionists. The events that would go down in history as Bleeding Kansas were triggered in 1854 by the Kansas-Nebraska Act, canceling the Missouri Compromise (which had until then guaranteed a balance between supporters and opponents of the slavery) and proclaiming that the status of the new state of Kansas would be determined by popular sovereignty.
This decision provoked the massive arrival on Kansas of activists of both sides who clashed violently, in the guerrilla mode, for the control of it. On November 21, 1855 the Wakarusa War began when an anti-slavery was killed by a pro-slave. On May 21, 1856, a group of Border Ruffians sacked Lawrence, a small town with anti-slavery theses. The next day, in the Senate, Preston Brooks, a Democrat from South Carolina, knocked out Charles Sumner, a Massachusetts senator and supporter of abolition. On the night of May 24, 1856, John Brown, who arrived in Kansas in October 1855 to fight slavery, slaughtered at Pottawatomie Creek a group of alleged slavers. On June 2, Brown captured about 30 slavery supporters at the Battle of Black Jack. In August 1856, thousands of slavery supporters, organized as armies, invaded Kansas. John Brown and his followers fought a part of it at the Battle of Osawatomie. Hostilities continued for two months until Brown and his followers left Kansas. A total of 56 people were killed in the Bleeding Kansas events.
