The Guerrilla War broke out in Kansas between pro-slavery and anti-slavery groups. The war continued from 1854-1861. This war is also referred to as a mini civil war.
In 1856, the conflicting groups of Kansas decide to create two groups, pro-slavery, and free-state. The pro-slavery claimed Lecompton as their headquarter. The free-state claimed Topeka. However, the pro-slavery group was one for violence, and 800 people from pro-slavery surrounded a state known for free-state beliefs, and destroyed a building.
On May 21st in the congress building in Washington, violence breaks out between 2 congress members. One being Preston Brooks, a pro-slavery member, and Charles Sumner, an opposing side member. Preston Brooks violently attacks Sumner with a cane repeatedly on the head, causing major brain damage. The free-state group was not going to allow this to happen without some retaliation, so John Brown, a free-state member, musters a group of men together, and heads to a pro-slavery settlement, and starts killing members. This is where John Brown gets the title “Pottawatomie Brown” as Pottawatomie Creek is the settlement where this occurred that night.