Depopulation of Native Americans Through Destruction

How did the Native Americans die and lose so many members of their population? Between the years of 1845 and 1870 there was a massive decline in the native American population. There are some who would say that disease and illness were the key factors to the depopulation of Native Americans, while others oppose and argue that the leading cause of the depopulation was due to killings and the nasty habits of the Europeans. "Sherburn F. Cook has estimated that sixty percent of the population decline in the years 1848 to 1870 was due to disease" (Rawls 175). Both David Jones and Colin Calloway suggest that the Native Americans lost population size for two very different reasons.