Would the Erie Canal have had the same effect if the United States had not made the Louisiana Purchase in 1803?

Honestly, I think the United States would eventually look the same as it does now. If they had not bought the land, they likely would have gone to war for it. It is very unlikely that they would have let it stay there as part of France or an independent country, both because of Manifest Destiny and for national security.

answer; talcott parsons;