How were the aztec and inca civilizations different from american indian civilizations in north america before contact with european explorers

1. If my memory serves me well, the Aztec and Inca civilization were different from American Indian civilization in North America before contact with European explorers, because they were generally larger and more politically intricate. They built big cities and they had their own language and government.

2. I am completely sure that the main difference between Northeastern Indian tribes and those who lived in the Mississippi were that Northeastern Indians created permanent agricultural villages. Other tribes were nomadic and hostile to others.

3. As far as I remember, the main reason why Europeans started their explorations in the 15th century were that they wanted to reach Asia. They tried to find a route to Asia as the majority of European countries were relatively poor and they needed to gain access to Asian resources.

4. The most suitable option which best describes the forced labor practices used by Spanish colonists in the Americas as part of the encomienda system is " Spanish missionaries required all non-Christians to serve as temporary slaves until they converted."