Answer:
The migration westward to settle in the frontier lands west of the Mississippi River
Explanation:
The migration westward to settle in the frontier lands west of the Mississippi River was the most prevalent migration trend in the United States between the end of the civil war and world war 1 because of the following reasons:
a. There was an opportunity to own lands cheaply and to become prosperous westward on the frontier lands west of the Mississippi river.
b. There was the presence of goldfield land westward and it resulted in mining opportunities of gold as well as mining or silver. This led to wealth creation.