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1519-1600Peer-reviewed · 2 sourcesDebated

Epidemic Disease Collapses Mexico's Indigenous Population

Smallpox and two waves of a mysterious hemorrhagic fever kill tens of millions within a single century

On the timeline · around 1519-1600 · Conquest and New SpainPre-Columbian MesoamericaConquest and New SpainEpidemic Disease Collapses Mexico's Indigenous Population900 CE1100130015001600

Quick facts

1519-1520 smallpox epidemic
Killed an estimated half of central Mexico's population
1545-1548 cocoliztli epidemic
5-15 million dead, up to 80% of survivors
1576-1578 cocoliztli epidemic
2-2.5 million dead, about 50% of remaining population
Population, 1519 vs. 1600
15-30 million vs. approximately 2 million

What happened

The smallpox epidemic that arrived with the Spanish in 1519 to 1520 is estimated to have killed roughly half the Indigenous population of central Mexico. Two further epidemics of a disease called cocoliztli, from 1545 to 1548 and again from 1576 to 1578, killed an estimated combined total of 7 to 17.5 million more people, up to 80% of the remaining Indigenous population in the first wave alone. Researchers who reanalyzed the 1545 and 1576 outbreaks found they were probably native hemorrhagic fevers rather than smallpox, carried by a rodent host and worsened by the most severe drought to hit north-central Mexico in 600 years, which concentrated stressed rodent populations near malnourished, drought-stricken human settlements. Mexico's population, estimated at 15 to 30 million before contact, had fallen to around 2 million by 1600.

Why it matters

This is one of the largest population collapses in recorded history, and it happened within living memory of the conquest itself: it emptied the labor base the encomienda system depended on, reshaped land ownership as Indigenous communal lands went vacant, and permanently altered the demographic balance between Indigenous, Spanish, and mixed-race populations that the later casta system tried to classify.

How we know

Tree-ring records reconstructing the 16th-century megadrought, combined with epidemiological reanalysis of contemporary Spanish accounts of symptoms (which do not match smallpox but do match hemorrhagic fever), let researchers separate the 1545 and 1576 cocoliztli outbreaks from the earlier, confirmed 1520 smallpox epidemic; the death toll is treated as an estimate because no census exists from the period, and different scholars have offered different ranges.

Sources

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Part of a timelineHistory of Mexico34 events · From the Olmec's colossal stone heads to a modern republic, told through the conquest that ended one empire and the revolution that remade the nation twiceView all →
Epidemic Disease Collapses Mexico's Indigenous Population · History of Mexico · SourcedStory