epidemics were just some of the causes of population decline during European contact. Intermarriage, slavery, wars, massacres, political disruption, economic changes, malnutrition, destruction of traditional subsistence patterns, and alcoholism also changed the composition of many Native American groups, whether they favored the changes or fought them. Eventually, these changes caused substantial depopulation and cultural change. This Native American depopulation occurred during the contact period, causing the Native American population size to decline from 1-18 million before European contact (c. AD 1500) to an estimated 530,000 by 1900.