It's 13 from the bottom in terms of income inequality. In terms of first world countries, upward mobility is the most dffficult. The USA is NOT unique relative to diversity or immigration. It's just another country in the new world. South Africa has 11 official languages. It has the best constituion in the world, according to scholars, and if you stand in Oxford street in London, you will hear a different language every minute.

The UK has more diversity in its little finger than America will ever have.