Peoples and Civilizations of the Americas, 600 ? 1500 Classical-Era Culture and Society in Mesoamerica, 600 ? 900 Mesoamericans were unified by similarities in material culture, religious beliefs and practices; they developed new forms of political organization, advances in astronomy, mathematics, improved agricultural productivity; cities were platforms/ pyramids fro religious functions; populations divided into classes, dominated by hereditary political/ religious elites, rural peasantry Teotihuac?n