The Maya civilization was biggest between the years of 420 AD and 900 AD. The Maya civilization spread all the way from central Mexico to Honduras, Guatemala, and northern El Salvador. It is estimated that at its maximum, the civilization had at least ten million people. The Maya people traded with other people in the Americas. Their art and buildings have many different styles. This shows they traded a lot. They made changes to their buildings to make them even better. The Maya civilization started getting smaller after 900 AD.