The Olmec emerged around 1500 BCE in the humid, river-cut lowlands of present-day Veracruz and Tabasco, and faded around 400 BCE. Their first great center, San Lorenzo Tenochtitlán, peaked around 1200 BCE; when it declined around 900 BCE, Olmec life shifted to La Venta and was finally abandoned roughly four centuries later.

The label 'mother culture' is contested — it does not mean that every later Maya, Zapotec, Teotihuacan, or Aztec feature derived directly from the Olmec. But it remains true that many shared Mesoamerican elements are first documented in Olmec contexts: the ritual ballgame, the jaguar-deity motif, the earliest steps toward writing (the Cascajal Block), the numerical bedrock of the Long Count calendar, and the use of cacao.

The signature of Olmec art is the colossal basalt heads, seventeen of which survive. The largest exceeds three meters and weighs some twenty-five tons. Faces are individuated; every headdress is unique; each is thought to portray a real ruler. The stone must have been hauled some ninety kilometers from quarry to San Lorenzo — much of it by river. In a context without the wheel in Mesoamerica, this logistics alone testifies to a central authority.

The Olmec left no written record we can yet read; most of what we know is reconstructed from excavation and from motifs that later Mesoamerican cultures borrowed. Nevertheless, they stand as the sole institutional center of the New World during the centuries when the Old World was passing through its Bronze Age.