In May of 1856 a pro-slavery jury out of Kansas said that the leaders of the anti slavery government committed treason. After, about 800 men went to arrest the leaders in the city of Lawrence. The antislavery leaders had fled by the time the men got there. Instead of arresting them they looted and destroyed the whole city. They also killed one man in the attack, this is known as the Sack of Lawrence.
After the Sack of Lawrence an abolitionist in Kansas wanted to fight back against the Pro-slavery people. His name was John Brown. On may 24, 1856 John Brown and his men killed 5 pro-slavery men on the Pottawatomie creek. This is known as the Pottawatomie Massacre. John Brown and his men also took the pro-slavery men from their home and killed them with swords. He said that he did this because God told him to. Afterwards Kansas fell in to civil war, this was known as Bleeding Kansas.
Congress reacted to the Sack of Lawrence also. Senator Charles Sumner criticized pro-slavery people and insulted Andrew Pickens Butler a pro-slavery senator. Preston Brooks took offence to the insult. May 22, 1856 Brooks went to Sumner and beat him with a walking cane. Brooks only had to pay $300 to the federal court. It took Sumner three years before he was better.