I've tackled a few similar questions already, as have others, so I'll just link to those. If you have any follow-up questions, feel free to ask them here.

• What differences caused the Mesoamerican societies to be much more successful than Eastern North American societies?

• The Natives of South and Central America always seem to have been incredibly ahead of their neighbours in North America. Why is that?

• Why are there no ancient Native American cities in North America?

• Why were Native American populations in South America so much larger than North?

• Why are there no pyramids or temples in North America, but there are so many in South America?

• Besides the Aztec and Mayan script, where there any other forms of writing, or recording information in Pre-Colombian North and South America? And if so, are there any collections of these works that tell us about Pre-Colombian America?

I'm sure there are more, but that should be enough to get your started.