Despite the focus on disease, epidemics alone were not enough to crash Native American populations after contact. The toxic colonial cocktail of disease, instigated warfare, slaving raids, territorial displacement, and resource restriction all worked together to decrease population size, and then prevent subsequent recovery. These shocks of contact hit at different times, and different places, leading to a highly nuanced demographic story in the years following contact.

The 90-95% mortality due to infectious disease figure that dominates the popular discourse has its foundation in the study of conquest-period Mexico. Several terrible epidemics struck the population of greater Mexico (estimated at ~22 million at contact) in quick succession. Roughly 8 million died in the 1520 smallpox epidemic, followed closely by the 1545 and 1576 cocoliztli epidemics where ~12-15 million and ~2 million perished, respectively (Acuna-Soto et al., 2002). After these epidemics and other demographic insults, the population in Mexico hit its nadir (lowest point) by 1600 before slowly beginning to recover.

Though the data from Mexico represents a great work of historic demography, the mortality figures from one specific place and time have been uncritically applied across the New World. Two key factors are commonly omitted when transferring the 90-95% mortality seen in Mexico to the greater Americas: (1) the 90-95% figure represents all excess mortality after contact (including the impact of warfare, famine, slavery, etc. with disease totals), and (2) disease mortality in Mexico was highest in densely populated urban centers where epidemics spread by rapidly among a population directly exposed to large numbers of Spanish colonists. Very few locations in the Americas mimic these ecological conditions, making the application of demographic patterns witnessed in one specific location inappropriate for generalization to the entire New World.

Any examination of disease epidemiology after contact must incorporate a larger ecological perspective, and one story, like the narrative of mortality in Mexico, won't adequately explain demographic trends over hundreds of years on two continents. Epidemics require the proper conditions for the host, the pathogen, and the environment to spread widely. Too often the narrative of “death by disease alone” fails to examine the greater context that facilitated the spread of epidemics. Infectious agents are treated as an inevitable miasma spreading ahead of contact, but the ecological context underscores how pathogens spread in conjunction with the repercussions of conquest. In the Florida missions, early disease outbreaks failed to travel beyond the immediate mission environs due to contested buffer zones between rival polities. Only after English slaving raids changed the social environment, erased these protective buffer zones, and destabilized the region did the first verifiable smallpox pandemic sweep the greater U.S. Southeast.

When attacks by slavers disrupted normal life, hunting and harvesting outside the village defenses became deadly exercises. Nutritional stress led to famine as food stores were depleted and enemies burned growing crops. Displaced nations attempted to carve new territory inland, escalating violence as the shatterzone of English colonial enterprises spread across the region. The slave trade united the Southeast in a commercial enterprise involving the long-range travel of human hosts, crowded susceptible hosts into dense palisaded villages, and weakened host immunity through the stresses of societal upheaval, famine, and warfare (Kelton). All of these factors were needed to propagate a smallpox epidemic across the Southeast, and all of these factors led to increase mortality once the epidemic arrived.

The myth of catastrophic disease spread often cites an incredibly high case fatality rate (number of people infected who die of that disease) for introduced pathogens in the Americas. We hear that an infectious organism like smallpox, which historically has an overall fatality rate of 30%, killed 95% of infected Native Americans. Taken without reference to the greater ecological situation, and assuming the validity of colonial mortality rates (a large assumption), the myth arises of an immunologically weaker Indian population unable to respond to novel pathogens.

Examining the greater context reveals how the cocktail of colonial stressors often stacked the deck against host immune defense before epidemics arrived. Plains Winter Counts recount disease mortality consistently increased in the year following nutritional stress (Sundstrom), and this link was understood by European colonists who routinely burned growing crops and food stores when invading Native American lands, trusting disease and depopulation would soon follow (Calloway). Mortality increased in populations under nutritional stress, geographically displaced due to warfare and slaving raids, and adapting to the breakdown of traditional social support systems caused by excess conquest-period mortality. Context highlights why many Native Americans, like modern refugee populations facing similar concurrent physiological stress, had a decreased capacity to respond to infection, and therefore higher mortality to periodic epidemics.

Even given periodic waves of pathogens, epidemics were not an automatic cultural death sentence. Humans are demographically capable of rebounding from high mortality events, like epidemics, provided other sources of excess mortality are limited. In the mid-twentieth century when the Aché of Paraguay moved to the missions ~38% of the population died from respiratory diseases alone. However, the Aché rallied quickly and are now a growing population. The key factor for population survival after high mortality events is limiting other demographic shocks, like violent incursions from outsiders, providing sufficient food resources, and the territory needed for forage and hunt to supplement food intake.

When the colonial cocktail arrived in full force demographic recovery became challenging. Warfare and slaving raids added to excess mortality, while simultaneously displacing populations from their stable food supply, and forcing refugees into crowded settlements where disease can spread among weakened hosts. Later reservations restricted access to foraged foods and exacerbated resource scarcity where disease could follow quickly on the heels of famine. The greater cocktail of colonial insults, not just the pathogens themselves, decreased population size and prevented rapid recovery during the conquest.

Sources:

Cameron, Kelton, and Swedlund, eds. Beyond Germs: Native Depopulation in North America

Etheridge & Shuckhall, editors Mapping the Mississippian Shatter Zone: The Colonial Indian Slave Trade and Regional Instability in the American South

Kelton Epidemics and Enslavement: Biological Catastrophe in the Native Southeast 1492-1715

Panich & Schneider, editors Indigenous Landscapes and Spanish Missions: New Perspectives from Archaeology and Ethnohistory

Sundstrom (1997) “Smallpox Used Them Up: References to Epidemic Disease in Northern Plains Winter Counts, 1714-1920.”