Question

How did the concept of Manifest Destiny create the need for the Missouri Compromise? As the US expanded, there needed to be a balance of power between the North and the South, which led to the Missouri Compromise. As the US expanded, slavery would be necessary to encourage agricultural growth, which led to the Missouri Compromise. As the US expanded, Northern and Southern states sought a way to eliminate their differences, which led to the Missouri Compromise. As the US expanded, there needed to be a way to prevent territories from becoming states to avoid conflict, which led to the Missouri Compromise.

Answer 1

The best answer is:
As the US expanded, there needed to be a balance of power between the North and the South, which led to the Missouri Compromise.

The massive territory acquired in the Lousiana Purchase, and the relatively even division of political power in the US regarding slavery at the time, meant that the new territory would prove to be a game-changer as states were created from it that either opposed or favored slavery. For this reason, Missouri and Maine were admitted as slave and free states, respectively, to keep the political balance even, and slavery was outlawed in all future states north of the 36th parallel for the same reason. 

Answer 2

as the US expanded there needed to be a balance of power between the north and the south