Respuesta :
The antebellum period was the period before the civil war where the gradual polarization of the country started between abolitionists and slave supporters. Meanwhile, northern states were mainly manufacturers, in the south cotton plantations were still very profitable. With the invention of the cotton gin the demand of cotton rose, even more, these plantations depended on slave labor to continue and this is one of the reasons the abolition of slavery wasn’t in the plans of the southern states.
By 1843 many slaves would run to the north so they could escape slavery. This made the relationship between states very unstable. The Fugitive Slave Law of 1850 made possible that any alleged or suspected runaway slave could be arrested. The suspect couldn't ask for a trial or testify on his/her own behalf. Any person who helped any runaway slave would be arrested for 6 months and pay a fine. Any officer that captured a fugitive slave would get a bonus or promotion. This law increased the issue with the anti-slavery citizens in the northern states.
In 1846 The Wilmot Proviso was a proposal that tried to ban slavery in the new territory acquired from the American-Mexican war. The North congressman David Wilmot feared that it would be possible that a pro-slave territory would be added so he proposed an amendment to the bill. This made the controversy over slavery even bigger. The failure of The Wilmot Proviso led to the Compromise of 1850 that helped to cool things down for some years before the civil war.
The Antebellum period is considered the period before the civil war. The next three events made sectionalism worse before the war.
1.- The Missouri Compromise.
To maintain the balance of power in Congress where polarization between slave and free states was becoming an unsolvable problem, the Missouri Compromise was approved in 1820. The Act allowed Missouri as a slave state and Maine as a free state.
In 1823, the Missouri Compromise was declared unconstitutional by the Supreme Court in the Dred Scott decisión. The decisión stated that Congress did not have the authority to prohibit slavery in the states.
2.- The Mexican-American War .
With the Mexican war against the United States(1946-1948), derived from the U.S. annexation of Texas in 1945, the Abolitionists saw the war as an attempt by the states that approved slavery to extend it even more and increase their power with the creation of additional slave states out of recent “acquired Mexican” territories-.
3.- The Kansas-Nebraska Act.
Probably, the Kansas-Nebraska Act was the main reason to start the civil war. People who wanted to move to Nebraska was not allowed to do so until the land was organized as a territory. People couldn't legally hold a claim on that land. That portion of the land had been prohibited slavery by the Missouri Compromise.