A-they needed to stay in the same place their plants where growing
Answer:
In Mexico the Olmec is considered the first significant civilization who are believed to have lived in the present day Veracruz and Tabasco. Following Olmec was the great Mayan civilization who occupied a large are including southeastern Mexico and Central America. Aztec a well-documented culture also known as Mexica culture. And lastly the Inca or Incan Empire in South America which is probably the largest empire in early 16th century.
Control of the sumerian where given mostly to temples,palaces,and big business families
