At the time of the Missouri Compromise, there was conflict between the North and the South because of

The North and South had different regional economies: the North relied more on industry and wage labor, while the South depended heavily on plantation agriculture and enslaved labor. As the United States expanded, they argued over whether slavery would be allowed in new territories, including land affected by the Louisiana Purchase. The Missouri Compromise addressed this sectional conflict, so “differences in regional economies” is the correct choice.

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