The world was a dissapointment, not how everyone from the past would have thought about it.
After the rebelion, America was left in a state of anarchy for the last century loosing all contact with other continents. Leaving rukus everywhere, and crazy people trying to control themselves.
Obviously many groups of powerfull people had conspire to what they called "great plans to conquer the Americas", but as you might guess... FAILED. It was fail after fail with more disaster in each one. But no one ever understood, each generation of man kind was more stupid than the previous one.
America was a mess, burned places, fire here and there, random people running from side to side looking for food and water.
One day, unexpectedly, when everyone was tired of conspiring to conquer America, an Asian emperor from a small country that no one knew about, came with the purpose that many people wanted to accomplish long ago.
So he went around on his llama, and apprehended people and sent them to a jail that he had built. And little by little he cleared up everything, and he and his llama conquered the Americas.