The first truly complex society in the Americas was that of the Olmec.
The earliest know major civilization in Mexico were the Olmecs. They followed a continuous development in Soconusco and lived in south-central Mexico’s tropical lowlands, which is the present-day states of Tabasco and Veracruz.
The Olmecs proposed during the formative period of Mesoamerica, dated roughly from around 1500 BCE to around 400 BCE.