Recent estimates for the size of the aggregate North American Indian population in A.D. 1492 vary from about 18 million to less than 2 million. The unusually favorable archaeological characteristics of Mohawk Iroquois sites in eastern New York have allowed a detailed demographic reconstruction of one case for the period A.D. 1400 to 1776. The case indicates that exogenous epidemics did not reach the region until the 17th century and supports arguments favoring the lower populations estimates for North America as a whole.