Olmec peoples
were the first culture to assert a surviving style of art and architecture during the Pre-Classic Period, when they established communities along the Gulf of Mexico by clearing the dense forestation for farmland and pastures, while constructing massive earth mounds used for political and religious purposes. Similar to the social structure first codified in Mesopotamia, these priest-kings probably had sole access to the sacred man-made mountains, while most people must have lived in wood and thatched dwellings clustered outside the ceremonial center. (Palmer, 2008)