In 1850, a compromise was devised that created a new regulation in new states, popular sovereignty. Popular Sovereignty is the idea that people can decide for themselves by voting if they wanted it or not. This overrode the idea of the Missouri Compromise of 1820 that created the 36 30 line that made a rule for where slavery was outlawed.
I HATE SLAVERY
As apart of the Compromise of 1850, the Fugitive Slave law was introduced. This made the rule that many states followed, "Once Free, Always Free" which meant that if a Fugitive Slave got to a free state, they were free, it made the rule invalid. This law made slave owners and slave catchers allowed to go into a free state and pull out blacks. Fugitive or not.
Dred Scott Decision
In 1852, Harriet Beecher Stowe wrote one of the most impactful books ever. This book, Uncle Tom's Cabin, was about the life of a fugitive slave girl, Eliza, and her escape from slavery. This book made many get fired up about slavery.
Lincoln v. Douglas Debates
In 1854, havoc was breaking out in Kansas. With the 1850 declaration of popular sovereignty, pro-slavery and freesoilers were in war. Men and woman from Missouri and other slave states were moving into Kansas to spread slavery west. Abolitionist from the North, such as John Brown to stop the spread of slavery
In 1857, the US Supreme Court made the most infamous decision ever. Slave Dred Scott filed for his freedom because he had been in the free Wisconsin territory with his master. The first decision the court made was that since Scott was a slave and not a citizen, they couldn't take his case. They also decided that the Missouri Compromise was wrong because it deprived people of their property, (slaves).
He is not a citizen!!
In 1858, there was an election for the senator of Illinois. The reigning senator was Stephen Douglas. His opposer, future president Abraham Lincoln. Douglas was running for the well known Democrat party. Lincoln, was running for the newly formed Republicans. He suggested that him and Douglas should have public debates for the people to watch. This brought much attention especially since the subject was slavery.