1200 BC

San Lorenzo Tenochtitlán

San Lorenzo enters its peak early Olmec phase

The date is not a birthday. San Lorenzo had already been occupied for roughly six centuries by the time the listing has a civilization appearing there.

A phase boundary, not a founding

Around 1200 BCE archaeological chronology marks a transition at San Lorenzo, from the San Lorenzo A phase of roughly 1400–1200 BCE into the peak San Lorenzo B phase of about 1200–1000 calibrated BCE.

Refined chronology puts occupation of the site from about 1800 to 800 calibrated BCE, with several phases preceding 1200. Older publications used uncalibrated radiocarbon and often gave the San Lorenzo phase as 1200–900.

This is an archaeological phase boundary, not a written date or a witnessed event.

What the peak phase looked like

During this phase San Lorenzo was a large constructed landscape with public monuments and an administrative complex, holding an estimated 8,000 to 18,000 people — and no royal graves have been found there.

Its builders reshaped a plateau rather than raising a single founding monument, and the basalt for the colossal heads came from a source roughly 80 kilometres away across difficult terrain. The sixteen known heads from San Lorenzo, La Venta and Tres Zapotes stand 1.47 to 3.4 metres and weigh 6 to 25.3 tons.

The development followed the spread of maize agriculture and sustained communal investment in platforms, engineered structures and gathering spaces — not the sudden appearance of a civilization from nothing.

"First in Central and North America" overreaches

San Lorenzo lies in present-day Veracruz, in southern Mexico rather than Central America, and the defensible claim is that it was the centre of Mesoamerica's first large, complex society.

Complexity was not confined to the Gulf Coast: by the Locona phase, about 1400–1250 BCE, communities on the Pacific coast of Chiapas were already building large architecture and importing obsidian and jade.

"Olmec" is a modern label derived from the later Nahuatl Olman, place of rubber; the inhabitants left no deciphered text naming themselves, their rulers or a founding year.

Sources

Researched 24 Aug 2026 8 sources not yet audited Date disputed

How this was checked

Researched from the web into a fact sheet and rewritten from that sheet. This article has not yet had an independent model audit. How the pipeline works →

Date disputed. Sources disagree; the research places it at ~-1200.

What the sources leave uncertain

The date is an archaeological phase boundary, not a written date or witnessed event.
Older publications used uncalibrated radiocarbon and often placed the San Lorenzo phase at 1200–900 BCE; newer calibrated chronologies begin important San Lorenzo development earlier and place the peak B phase at 1200–1000 BCE.
Civilization is an analytical label whose criteria vary. San Lorenzo can responsibly be called Mesoamerica’s first large, complex center, but broader claims about all North and Central America require qualification.
The inhabitants left no deciphered historical text identifying themselves, their rulers, or a founding year.