Why did new problems about the spread of slavery
come up after the Missouri Compromise?

The Missouri Compromise created new problems dealing with slavery since it divided America even further and let in Missouri as a slave state and Maine as a free state which balanced out the US Senate. This led to more tension between people who believed and did not believe in slavery. It ultimately led to Bleeding Kansas and pushed America toward the Civil War by adding wood to fire the fire of sectionalism in the US and creating much more tension between the states.

Explanation:

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your answer would be (b)

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