Northern states were 'free states' and Southern states were 'slave states'. It created divide between North and South as they wanted to move west.
1820 Missouri Compromise allowed Missouri to become a slave state but made sure that states in the north were free and in the south were slave.
1850Compromise let California become a free state because it fell in the middle of the latitude. It also allowed new fugitive slave laws -escaped slaves could be returned to their owners.
1854, Kansas Nebraska Act let Kansas and Nebraska territories choose whether they wanted to be free or slave states. Many travelled there to choose and as a result, many riots took place there.
1853, Harriet Beecher Stowe published Uncle Tom's Cabin which provoked many to join abolitionist groups.
1857, Dredd Scott was an enslaved man, who went to court because he lived in a free state and was still considered a slave.
1859, John Brown led an attack on Harper's Ferry, Virginia in an attempt to start a raid. He failed and was executed.
Abraham Lincoln was elected in 1860 by most northern states, however created divide because Southerners hadn't elected him - they felt they had no say.
1861 was the secession of the south, where 11 states, following South Carolina, had left the Union to make their own country called the Confederacy. They elected Jefferson Davis as their President.
1861, Fort Sumter, South Carolina was where the first shots of the Civil War were fired by the Confederacy to the Union.
The American Civil War took place between 1861 and 1865.