The figure was never that high and it was over decades. Tribes were too small and scattered for a single mass epidemic to kill that many.
Exactly. Now while it is true that disease killed about 90%, that was over several centuries.
Population densities were indeed too small for it to be like COVID, where it sweeps a nation in a week or so. Even in a much more densely populated Europe, the Bubonic Plague still took almost a decade to cover the entire continent. And Europe is less than half the size of North America. The 80-90% figure is accurate, but that is over hundreds of years. And for the most part the death rates decreased as tribes built up resistances, and today the Indians are no more susceptible to diseases than any others in the country.
And it was multiple waves of very different diseases. Measles, Chicken Pox, Flu, Small Pox, it was multiple diseases striking different areas at different times. Even into the mid-1800s, tribes were falling victim to diseases they had never encountered before. And in the 19th century, that was finally affecting some of the more remote tribes like the Maidu.
They were largely isolated in the Sierra-Nevada Mountains, and had little contact with Europeans prior to the Gold Rush, so had been spared much of the impact of diseases. But they also lived in Gold Country, so the sudden influx of a flood of people literally from all over the world (including the Eastern US, Europe, Africa, even Asia) suddenly brought in a huge number of diseases they had never been exposed to before and it decimated their numbers. And that was well over 350 years after Europeans discovered the continent.
And that is why when anthropologists today meet remote tribal groups, they are very careful about how they do so. Mostly because they do not want to introduce diseases they had never been exposed to before. Because there are still groups of people on the planet that have had little to no contact with outsiders. One of the worst accidental ones in recent history was the Panara in Brazil. No contact with outsiders, but a highway was built through their territory in 1973. And within a year over two-thirds of the tribe was dead from disease.
Another was in 1981 when the Nukak tribe was first contacted in Columbia. With almost the same result, most of the tribe dying due to disease within a year.
That is why some areas like those on North Sentinel Island are now protected, with contact with the people there prohibited by law.
