Prior to 1812 most americans lives. a) west of the mississippi b) along the atlantic coastline c) southwestern plains d) in the northwest of the united states

The most accurate answer is

D. In the northwest of the United States

 In the 1800's most American's lived in the East Coast 
The reason why most Americans moved to the east was because 
most of them would be slaves or farmers looking for their own land. Some people worked for people though like some people would farm others land.

Glad to help :)