Who immigrated and why, and how did immigration impact urbanization?

Who immigrated and why:

Many parts of the world decided to leave their homes and immigrate to the United States, They did this because they wanted greater economic opportunity.

How did it impact urbanization?:

It impacted it by leaving a growth in many cities, commonly, factories were located near urban areas. These businesses attracted immigrants and people moving from rural areas who were looking for employment.

i have no idea lets guess a

explanation:

couples could only have one child to reduce the population growth.