The populations of cities in the time period between the Civil War and 1920 grew rapidly. Where were people moving to the cities from? Why did they flock to the big cities?

1. Where were they moving from? They were moving from rural area to urban areas.

2. Why did they flock to the big cities? They were moving to big cities in search of better paying jobs in the large factories.

Explanation:

Two biggest industrial revolutions have been seen in the history of the US.

The first wave was seen from 1700 to early 1800. This wave brought a rise in the factories.

The second wave was seen after the civil war. This wave bought rise in novel technologies such as telephones, vehicles, etc.

A large number of people migrated to the cities during these industrial revolutions in search of a better life.