How did Missouri compromise stop slavery?

Answer 1

The Missouri Compromise of 1820 did not stop slavery really. It only limited the area where new slave states could be created. The Compromise was that Missouri would be admitted as a slave state, but there could be no more new slave states north of 36 degrees, 30 minutes latitude, which is the line of the southern border of Missouri. So Missouri was entirely to the north of the permissable new slave territory. This was important because the territory of the Louisiana Purchase, acquired in 1803, was just becoming thickly settled enough to petition for admission as new states, so the agreement of the Compromise delineated where new slave states could be created, and the rest of the territory, when admitted as states, would be free states. Congress was careful after the Compromise to admit two states at a time - one slave state and one free state, to preserve the balance of power in Congress. This Compromise kept the issue from erupting into conflict for a generation, until more territory, the vast expanse obtained from Mexico as a result of the Mexican War in 1848, once again brought the issue of where slave states could be created back to the front burner.