Answer:
All northern states had abolished slavery by 1830, however, in the South, slavery was more important and widespread than ever. The economy of the South depended on the slave labor working in cotton plantations.
Explanation:
This led to bitter disagreements between the North and the South about slavery. Some compromises were reached but the tensions continued.
The most important was the Missouri Compromise, which allowed Missouri to enter the union as a slavery state in exchange for the entrance of Maine as a free state. Besides, the Missouri Compromise prohibited slavery above the 36° parallel in the new territories. If this held true today, Arizona, New Mexico, and Southern California would be slave states.
Abraham Lincoln and the new Republican Party opposed slavery in all new U.S. territories, whether they were below the 36° parallel or not. When Lincoln was elected president, the South saw him as a threat for slavery in the South even if Lincoln neven explicitely said that he wanted to abolish slavery in all U.S. states.
This led to the secession of several southern states, the creation of the Confederacy, and finally, the Civil War.
