It all boils down to culture, for whatever reason, there is something about American culture that allows, no encourages people to succeed. People have come to this country, people from all races and culture, and have succeeded by embracing the culture pursuing their dreams.
I don't know what makes American culture the best, but I think it has something to do with being free, really free, to pursue whatever it is that fires your soul.
No other soceity, let you fail and fail and fail only to try again like America.
I know this for a fact, as I have failed so many times that I can't count them. One thing you always get (if you are not a felon) in America is a second chance