On the American continent the descendants of the Clovis people (perhaps descendants of other groups as well) spread throughout North and South America. These descendants of the early homo sapiens split off into many different tribal societies.
Three great early civilizations would emerge south of what would become the United States of America. These civilizations were: the Mayans, the Aztecs, and the Incas. In the area that would become the United States, at about the same time as the Dark Ages in Europe, there emerged a civilization known as the Mississippians. This civilization was a loose association of similar peoples with common language, customs, and beliefs.
Many great urban areas developed within the greater Mississippian territories. The Mississippians inhabited the Mississippi, Cumberland, and Tennessee River valleys. They were great traders and may have actually traded throughout half of the North American continent. Some of the items that they traded were: pottery, copper, gold, silver, conch shells, and fabric.
For food the Mississippians hunted and fished, but also raised maize, beans, and squash. In some areas these people managed ponds where they raised fish.
Much like the Egyptians and other early civilizations the Mississippians built pyramids. However, their pyramids were made with dirt and grass and were flat on top. Sometimes the ruler of an urban area would live on the top of a pyramid (also referred to as a mound). Mostly though, the mounds were used for religious ceremonies.