[Eric in the Ozarks]

Mann, the historian, says the big difference was the lack of resistance. Only a comparative handful of Europeans arrived between 1519 and 1623. The indigenous population dropped from about 25 million to about 700,000 in about 100 years, a 97 percent reduction.
Hantavirius was called “Cocolitli” by central Americans. Small pox was the chief killer and is described unmistakably in 16th century drawings.

[muawiyah]

"Resistance" is only a small part of the equation. The English colony at Jamestown suffered about 60,000 deaths in its first 20 years (one of the reasons they relocated to Williamsburg).

Given the number of new arrivals that was a death rate to equal the worst Indian death rates.

Recall, at the time of initial settlement (1609) Virginia was just now at the end of nearly half a century of semi-arid conditions within which was a 17 year drought sufficient to have driven EVERYONE to live above the Fall Line. Those conductions always presage a major hanta virus outbreak once the drought breaks and the grasslands return.

Other historians have noted a similar period up the coast in the decade prior to the 1646-48 die-offs.

It was not the case that white folks just stood around and watched Indians died. Everybody died. The whites had backup resources in Europe. The Indians didn't.

Mann's estimate of 25 million is far too low. The agricultural base extant in the Americas at the time of first contact was far too large for such a small population.

Even if the Indians had had superior technology and were discovering Europe and Africa, they'd still died off in the Americas ~ as they had been doing for thousands of years.