Road to Secession

Congress passed a bill granting Missouri statehood as a slave state under the condition that slavery was to be forever prohibited in the rest of the Louisiana Purchase north of the 36th parallel, which runs approximately along the southern border of Missouri.
The north's perspective on it was that they were not happy when they heard that Missouri was going to be put in as a slave state, it would not be fair because if would disrupt the balance of the slave/anti-slave balance
The south's perspective was that at first, were very pleased with the balance of slave states in their favor and argued with the North about whether or not they should change the balance of the states to make it equal for both slave and anti- slave states.

The Texas annexation was the 1845 annexation of the Republic of Texas into the United States of America, which was admitted to the Union as the 28th state on December 29, 1845. The Republic of Texas declared independence from the Republic of Mexico on March 2, 1836.
The northerners opposed the annexation of Texas because they objected the spread of slavery on either moral or economic grounds and they predicted that admitting Texas would lead to war.
The Southerners agreed to the annexation because they wanted to extend slavery.

In 1849 California requested permission to enter the Union as a free state, potentially upsetting the balance between the free and slave states in the U.S. Senate. Senator Henry Clay introduced a series of resolutions on January 29, 1850, in an attempt to seek a compromise and avert a crisis between North and South.
The southerners supported the compromise of 1850, because it gave them the opportunity to make more slave states.
The northerners were unhappy with the idea, because it meant that the new states could be slave states. It also started the Fugitive Slave Act.

Uncle Tom's Cabin; or, Life Among the Lowly, is an anti-slavery novel by American author Harriet Beecher Stowe. ... The sentimental novel depicts the reality of slavery while also asserting that Christian love can overcome something as destructive as enslavement of fellow human beings.
The northerners realize how unjust slavery was for the first time.
The southerner slave owners worked even harder to defend the institution.

It allowed people in the territories of Kansas and Nebraska to decide for themselves whether or not to allow slavery within their borders. The Act served to repeal the Missouri Compromise of 1820 which prohibited slavery north of latitude 36°30´.
The north opposed the act because they did not want kansas to be a slave state
The southerners supported slavery or for political reasons wanted Kansas counted as a state that favors slavery

Sandford, legal case in which the U.S. Supreme Court ruled (7–2) that a slave (Dred Scott) who had resided in a free state and territory (where slavery was prohibited) was not thereby entitled to his freedom; that African Americans were not and could never be citizens of the United States;
Southerners approved the Dred Scott decision believing Congress had no right to prohibit slavery in the territories.
The north believed that the supreme court only did it to keep peace with the south and keep the country together.

John Brown's raid on Harpers Ferry was an 1859 effort by abolitionist John Brown to initiate an armed slave revolt in Southern states by taking over a United States arsenal at Harpers Ferry, Virginia. It has been called the dress rehearsal for the Civil War.
The south saw it as an opportunity to push their ideas of african americans and how they need slavery.
The north admired his bravery and courage and fighting for a great cause, he was hugely supported by the north.

In a four-way contest, the Republican Party ticket of Abraham Lincoln and Hannibal Hamlin emerged triumphant. The election of Lincoln served as the primary catalyst of the American Civil War.
The north supported him and the idea to abolish slavery and believing everything the union stood for.
The south was furious with abraham lincoln in office. Slavery was a big part of what they believed in and they believed that the north didn't give them a fair chance at a vote.

Southern states that seceded immediately after Lincoln's election in 1860 did so because they had already been planning it in the event of a Republican victory. Their motivation involved what they perceived as a threat to the institution of slavery, which their economy was dependent upon.
The south's perspective of the secession was that southern states' desire to preserve the institution of slavery. Others minimize slavery and point to other factors, such as taxation or the principle of States' Rights.
The north's perspective was they thought it was another loss in trying to keep the country together and believed it was unnecessary.