Second, the popular narrative tends to paint disease alone as the culprit for Native American population decline. In North America we have tremendous difficulty teasing out the influence of disease mortality from the greater colonial cocktail of warfare, territorial displacement, the Indian slave trade, social disruption, and famine that often worked together to (1) spread disease and (2) weaken host immunity to increase their susceptibility to infectious disease. I’m most familiar with the U.S. Southeast, so I’ll use this as an example to highlight this difficulty.

In the Florida missions, started in 1565, 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 through the greater U.S. Southeast in the late 1600s. 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.

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.

So, returning to your question, before ~1700 most areas of disease mortality in North America were relatively limited to coastal populations, and those with direct contact to high numbers of European colonists and traders. For example, the epidemic that decimated coastal New England from 1616-1619, leading to population constriction among the Wampanoag that left abandoned villages, and their corn stores, ready for the Pilgrims arrival in 1620, does not appear to have spread inland. Measles burns through Northern Iroquoian groups in 1634-1635, likely introduced through French Canada, but is followed by a devastating smallpox epidemic introduced by the Dutch on the Connecticut and Hudson Rivers in 1634 that halved the population size of most of the Five Nations. It is only after ~1700, with the corresponding increase in European immigrant population size, increased trade connections, and a dramatic increase in the scale of warfare and displacement that we see very large, pandemic-style epidemics in the hinterlands.

The first confirmed smallpox pandemic in the Southeast occurred from 1696-1700 followed the paths of the Indian slave trade from the Atlantic Coast all the way to the Mississippi River, where French traders and Jesuit fathers recorded substantial mortality in the years preceding their arrival. 51 Northern Plains Winter Counts record some instance of infectious disease between 1682 and 1920. If we ignore the earliest Winter Counts (due to lack of cross-reference capacity) and focus on the time period from 1714 to 1919, Native American populations on the northern plains endured 36 major epidemics in two centuries. An epidemic occurred roughly every 5.7 years for the entire Northern Plains population, but varied by band. The Mandan saw the recurrence of epidemics every 9.7 years, while the Yanktonai averaged an epidemic every 15.8 years. The longest epidemic free interval for any band was 45 years for the Southern Lakota, and the shortest was 14 years for the Mandan. Northern Plains pandemics, when an epidemic effects all, or nearly all, of the Northern Plains populations, occurred in 1781 (smallpox), 1801 (smallpox), 1818 (smallpox), 1837-38 (smallpox), 1844 (measles or smallox), and 1888 (measles).

What do all my ramblings here us about disease events well beyond the frontier? Epidemics of infectious disease occurred before significant, sustained face-to-face contact with Europeans (for example, 3-5 epidemics before the establishment of permanent trading posts on the Northern Plains). After ~1700 epidemics of infectious disease seem to have arrived in waves, one roughly every 5 to 10 years, burned through the pool of susceptible hosts, and left long periods of stasis in their wake. An entire generation could be born, live and die between waves of disease for some bands, while others were hit with multiple events in quick succession. Even in the same epidemic of the same pathogen, mortality could differ based on immunity from previous exposure and the stressors (famine, poor nutrition, displacement, etc.) influencing the health of the band.

One final note, I really hate to emphasize disease alone when talking about Native American population dynamics after contact. 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 after contact.

Sources:

Acuna-Soto et al., (2002) “Megadrought and Megadeath in 16th Century Mexico”

Beck Chiefdoms, Collapse, and Coalescence in the Early American South

Calloway One Vast Winter Count: The Native American West before Lewis and Clark

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

Snow (1996) The Iroquois

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