What are the major causes of immigration in the United States

Identifying a narrow area of interest, you decided to pursue:
– What are the major causes of immigration in the United States
– How has immigration affected American society.
– Are the Americans supportive of it?
– How it has affected their economy? Good or bad?
– Has the government treated the immigrants?
3. Report what is known about the area of interest you decide to pursue. This is a mini literature review you are going to write. Examine popular press, internet, and academic journals and compile some findings regarding your area of study (for example, authors X, Y, Z found that humor in advertising works in the U.S. but not in Korea, and they attribute this to the difference in national cultures).