The missouri compromise was a sign of the end of the era of good feelings because it

Well the Missouri Compromise was a compromise between north and south states, a compromise over slave states and free states. The admission of Missouri in to the union and Maine into the union sparked controversy. So the compromise made Missouri a slave state and Maine a free state. The compromise represented the growing tensions over the north/south and over slavery. (What if a single state were admitted, would it be free state? Then the slave states would get angry.)

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