To be honest, I dont know. I'm actually not an American. :)
But If i had to pick one major event...it would be making George Washington the president.
To explane.
George Washington's presidentsy in a way made America, in some aspects, what it is today.
Now imagine if he was not made a president but chose to be a dictator. I know its funny and my nest statement is going to be even funnier.
Assassins Creed 3: The rule of King George did a decadent job in imagining and explaning this. I recommend reading its plot, I think you would find it interesting. Its full of what ifs and alternative history events.
Sorry for not giving my version but its a bit hard for me to imagine something like that.
False next time try to look it up
There were many aspects that they inspired. Religion was one certainly where many religions were inspired by Mesopotamian or Egyptian gods and stories about them. Another is language and cultural heritage. Another is their knowledge of urbanization and agriculture that enabled them to focus their endeavors on other more spiritual things since they had this covered.
Answer:
The answer is varied. They have varied climate