From Europe’s discovery of the American Indian at the end of the fifteenth century to the present, the questions of who the native American populations are and how they came to the Western Hemisphere (North and South America and the surrounding waters) have intrigued scholars, clergymen, and laymen. The advancement of anthropology has yielded some answers: Since no skeletal remains of a human physical type earlier than Homo sapiens have yet been found in the Americas, researchers have concluded that the continents were settled through migration. Many scholars believe that Asians came to America during two periods: the first, between 50,000 and 40,000 B.C.; and the second, between 26,000 and 8000 B.C. They are believed to have come by way of a great land or ice bridge (Beringia) over the Bering Strait, between Asia (Russia) and North America (Alaska). (This causeway was covered by water from about 40,000 to 26,000 B.C. because of a period of melting, which would have prevented passage.)

Most scholars also agree that there were several discrete, and perhaps isolated, movements of various peoples from Asia to the Americas. The migrations might have been prompted by population increases in the tribes of central Asia, which impelled some to move eastward in quest of food sources—animals. As game moved across the Bering Strait, hunters followed.

Over time, population growth caused early man to continue southward through the Americas so that by 8000 B.C. there were primitive hunters even in Tierra del Fuego, which forms the southernmost part of South America. Around 5000 B.C. the disappearance of large game animals in both North and South America produced a series of regional developments, culminating in the emergence of several great civilizations, including the Inca, Maya, and Aztec.