Why is the United States called a nation of immigrants?

Because many immigrants came/come here, and it was built up of immigrants

List the sentences. keep in mind when you use sarcasm you are saying one thing in a tone to make it clear you are joking. like for instance, pretend you get a math test from your teacher. you’d most likely say, “oh yay.. a math test.” but you’d have the tone to give it the “oh come on” feeling. does this at all?