I think everyone forgets that the United States was founded on immigration. Too bad the Native Americans didn't form one nation to kick those Pilgrims out!
Can you just see it now?

(Swirly dream sequence.)

INS: What is your purpose in coming to these lovely shores?

Pilgrim #1: Uh, to plunder the land and conquer the people.

INS: Out! Out! Back home to England! Next? Why are you here, sir?

Pilgrim #2:To seek out a new life for myself and have the freedom to practice my own religion.

INS: Yeah, and you're going to oppress everyone who doesn't conform to YOUR beliefs, you dirty rotten Puritan. Next! What do you have in those blankets, ma'am?

Pilgrim #3: Smallpox. I figgered I'd give them Indians some blankets and pretend to be friendly. But the smallpox will wipe out their whole tribe! Then me and my man can till the soil and cut down a few trees, and in a few years we'll have the very first Pil-Mart shopping center.

INS: (Checks papers.) How long will your length of stay be?

Pilgrim #3: Oh, about five hundred years.