All nations. The US is just 234 years old; it is the baby of nations.
I wouldn't say that, some nations are constantly changing (weather it be there names or merging) so here my answer i was trying to type while you answered:
Many, the United States is one of the youngest nations there is. The oldest nation however is probably China. China was formed 221B.C.E whereas the US was formed in 1776C.E. For the less politically correct: 221B.C. and 1776A.D.
The frontier no longes existed in the us.
No. They existed for a reason; combating the US/allies. With the (communist) victory in 1975...their reason for existence no longer existed.
edinburgh
If you mean the US, that is before the United States existed. If you refer to another nation, you need to specify.
Because there is the widest range of religions in America
no
Before Canada existed as a nation, Alaska was owned by Russia. Russia then sold Alaska to the United States.
Really long. Longer than a list of Donald Trumps lies. Longer than the Joe Biden has been senile. Longer than the US political system has been screwing US citizens.
Yes. The Mississippi River is longer than the Missouri.
Well, obviously yes. Think about it, the English Nation has been around for FAR longer than the (non-Native) American Nation. That's why American "History" is so short; so England must have had an government when the American settlers left/were exiled from England.
Yes
No.