Um. People from first world countries do NOT move to America. It has a terrible reputation, and the life quality and working conditions are terrible compared to those in the first world.

Most people who come to America are from the undeveloped world, and, yes, America is better than the undeveloped world, but it doesn't even remotely compare to the developed world.

For the record, I spent 11 years in America, 40 years in Africa, and the remaining 20 years in the UK and the EU (6 different countries).