How did the countries of origin and ability to assimilate differ among the waves of immigrants entering the United States during the late 19th and early 20th century?

Complete sentence please

Immigration isn’t exactly a new occurrence in the United States. Still, despite a rich history of welcoming strangers into the country, it seems that the voices of critics calling for stricter immigration policy only get louder and fears over the negative economic impact immigrants might have continue to grow. It’s worth asking, in a country where nearly everyone’s ancestral line includes an immigration story, how things got that way.

Explanation:

2. a land bridge connected asia and north america thousands of years ago.

4. crossing the land bridge would have been simple for the first migrants.

5. people might have crossed a land bridge while hunting animals.

c. businesses/firms & government