About 40,000 years ago, hunter-gatherers began migrating from Asia to the Americas. As they migrated, they began to spread into South America as well as east into the plains of North America. Over the years, these people adapted to their new environment by forming governments, constructing buildings and shelters, and gathering different types of food. Sometimes their location even facilitated trade with other neighboring societies. These hunter-gatherers then developed into what we call today: the Mayan, Inca and Aztec tribes. During the first centuries CE, the Mayan people began to build their civilization in central Mesoamerica. This location allowed the Mayans to trade and exchange their local products. They also participated in the slash-and-burn method of cultivation, but it appears that they developed other methods, such as planting on raised beds above swamps and on hillside terraces. Not only does place influence agricultural life, but it also influences all other aspects of life. The Mayans drew their influence from a neighboring society, the Olmecs. The Mayans mixed their customs with those of the Olmecs to create a culturally diverse society. These Olmec customs had a great influence on other aspects of Mayan society. The Mayans had a polytheistic religion with the gods of corn, death, rain and war. These religious beliefs led to the development of calendars, astronomy and mathematics. The Mayans developed two types of calendars: religious and solar. The religious calendar was based on the belief that "time was a burden carried on the back of a God." The solar calendar was based on observations of the sun, planets and moon. Unlike our calendar today, it consisted of twenty-five days...... middle of paper ......the religious capital, other cities also had religious purposes. The Inca Empire reached the height of its success during the reign of Huayna Capac. Capac received a bad omen from butterflies during a trip to Ecuador and a few weeks later died of illness. After his death, the empire was divided by his sons: Atahualpa received about a fifth of the empire and Huascar the rest. A bitter civil war followed these misunderstandings and the empire declined. These three complex North American societies had considerable influence on other parts of the world. They were not great empires but they left ruins as spectacular as those of ancient Mexico or Peru. These complex societies were able to establish commercial, traditional, and governmental empires as quickly as they declined. Nevertheless, today they constitute an important part of our world history..