The author chose to study early Americans after becoming interested in their history from a school unit. The document discusses three groups - the Mound Builders, Cliff Dwellers, and Aztecs. While the Aztecs left drawings and were very violent, the Cliff Dwellers made items from stone, shells, and rocks and lived in caves and cliffs. The author would want to be an Aztec to make artifacts from nature but not be violent like them.