How did "Bleeding Kansas" lead to the Civil War?
If you lived in Kansas, the Civil War began for you in 1855. This is when pro-slavery "border ruffians" poured into Kansas to attempt to establish that territory as a slave state. There they clashed with anti-slavery Kansans, as well as many people, like abolitionist John Brown, for example, that went there expressly to fight against slavery. The issue began when Senator Stephen Douglas extended the principle of popular sovereignty to the territory, which he organized under the Kansas-Nebraska Act. The fighting that led the territory to be known as "Bleeding Kansas" accompanied political intrigue and fraud over the establishment of a constitution for the territory. "Bleeding Kansas" can mainly be said to have led to the Civil War because it led to the establishment of the Republican Party. This development, which accompanied the collapse of the old two-party system that included the Whigs and the Democrats, made compromise between the North and South less likely. When the Republicans, whose platform called for a ban on the expansion of slavery, won the White House under Abraham Lincoln in 1860, South Carolina led the way in seceding from the Union. "Bleeding Kansas" played a major role in escalating tensions between the North and the slave states.
As tensions over slavery heated up in the 1850s, Congress decided to allow the citizens living in the Kansas territory to decide for themselves through the ballot whether or not the state would enter the union as a free or a slave state, a well-meant but ultimately disastrous attempt to defuse a volatile situation. This led both sides of the slavery debate, those who believed in freedom for all people and those who believed in slavery, to flood into the territory to try to influence the vote. Tensions escalated sharply, and violent incidents and clashes followed. Pro-slavers called "border ruffians" came over the border from Missouri, a slave state, and burned, looted, and killed in order to intimidate the abolitionists. John Brown, an abolitionist later famous for the Harper's Ferry raid, led a band of people in violence against the pro-slavers. Violence grew and erupted into a situation akin to a civil war. Though Kansas eventually came into the country as a free state in 1861, the events there helped legitimize the idea of violence as a solution to the slavery problem. The bloody events, and their use as propaganda by both sides also increased polarization and hatred, further hardening the uncompromising positions that led to the Civil War.