From where did people from the new world originate and why did they come

Scientists believe that people crossed from Asia from a Bering Strait, that was frozen during the ice age. This is just a theory, but scientists conclude they were probably hunting big game, looking for food, etc.

I hope this helped you!

They came from Spain, France, and England. 
 
Some came for religious freedom and some came looking for gold, and some wanted to conquer new lands.

Both the han and the roman empire decline as a result of social unrest during their collapse.