Native American is only one group there various other religious groups
eg Christians , Muslim , Hindus, Sikhs, Jews, Atheist , Amish , sciencetologist, Baha'i ,Unitarian Universalism etc...Many of which you may not even have heard outside US.
Industrial revolution did not come to US automatically...they too started with nothing and despite all those differences they have achieved everything.
US was not a rich country when civil war broke out there..one half of the country was fighting the other half...they were able overcome that too.
Its good that you mentioned USSR ...In 1987 when USSR was on its last breaths ..
president Gorbachev asked then PM Mr Rajiv Gandhi .." How India despite being poor country and having so many different ethnicities , languages ,religion is able to stay together"...in his reply Mr Gandhi wrote t..that in India every different group is allowed to keep their own unique identity ..which was not there in communist Soviet Union