Mesoamerican people devised complex ways of organizing society, government and religious worship and built remarkable cities with available technology. The earliest sign of technologies in Mesoamerica is the Clovis Point dated some 13,500 years, found in NM; these would have been used as a type of spear tips or knives and indicates a mobile culture that exploited the faunal resources available. Migration and trade spread cultural influences throughout the region long after the decline of the early empires. This diversity was heightened by the north/south orientation of the Americas, since the spread of crops and animals in temperate regions was impeded by the tropical zones of the equator Inhibited by natural barriers and the lack of domestic animals the Hopewell culture still survived over 1300 years in the Ohio and Mississippi valleys. Hundreds of structures were built that served as burial places for their leading citizens. These mounds show not only the skill but the sheer numbers of these builders and the complexity of their social structure, their elaborate religious rituals and their trading networks. Another mound culture, the Eastern Woodlands owed much of their prominence to farming. These people emerged as premier city builders and their towns spread out for hundreds of miles in every direction from their hub near modern day St Louis. At Cahokia more than 100 flat topped mounds were covered with religious temples and elite dwellings. By the middle of the 13th century, the Aztecs moved south from Mesoamerica’s northern frontiers and settled into Central Mexico. These people built large temples and palaces adorned with brightly painted images of gods, gardens and marketplaces, the Aztecs were also a highly stratified society and included some 500,000 people. The ruler or Chief Speaker shared governing power with the aristocracy and religious leaders, while commoners performed the labors. Although most of these early civilizations collapsed prior to the 15th century, the societies of pre-contact America were large, diverse and complex and would continue their influence centuries later.