While totals depend somewhat on how one defines the colonial period, rough estimates show that in the generations following the arrival of the Columbus expedition, between 90 to 95 percent of the Native American population that came in contact with white incursions perished.
Exact numbers regarding Native American death tolls vary among research scholars. Some claim numbers as high as 18 million dead, whereas others claim it was as low as 1.8 million. In any case, scholars nonetheless agree that the results for Native American societies, cultures, political structures and demographic integrity were utterly devastating, allowing Europeans an unparalleled facility in their search for land, labor and resources.
Of all the causes of Native American deaths during the colonial era, disease was by far the most devastating. While smallpox, brought by Europeans, is the most widely cited of these killer diseases, others, including typhus, influenza and bubonic plague, also played sinister roles. Although much of the transmission of disease to Native Americans is believed to have been unwitting, there is also evidence of episodes where transmission, indeed infection, was premeditated. If someone expands the notion of the colonial period to the era of the 19th century, the period which saw the greatest influx of white settlers into the North American west, then death tolls continue to rise precipitously.
A statement issued by the U.S. Census Bureau in 1894 suggests that, to that date, wars waged by the American government against Native Americans numbered at least 40. In those wars, estimates for Native American dead were at least 30,000 with the Census statement adding the caveat that the actual total for Native deaths must have actually been much higher — as much as 50 percent more.