Disease and intergroup contact.

After the arrival of Europeans, the indigenous population of North America began to decline. The Spanish intrusion, first into the Caribbean and then into the Southwest and Southeast circa 1520, launched a series of lethal epidemics that infected various indigenous peoples. The epidemiological conquest of North America accelerated after the early seventeenth century, which saw English and French colonization along the Atlantic Seaboard. The dramatic population decline of indigenous peoples continued until the early twentieth century. By 1920, the American Indian population of the United States was just 270,995, compared to an estimated 1.2 million to 18 million people who had inhabited North America at the time of the arrival of Europeans. American Indians Disease and intergroup contact