Introduction

Contemporary Americans value their rich cultural diversity. Since the late fifteenth century, the cultural diversity of the Western Hemisphere has been shaped by an influx of peoples from Europe, Asia, and Africa. In the process of this migration, the peoples already living in the so-called "New World" often were conquered, displaced, and decimated. But cultural diversity in the Americas did not begin with the Columbian age. Indeed, the societies that evolved in the Americas in the centuries prior to 1500 were marked by a high degree of cultural variation.

The great Amerindian empires-the Olmecs, Mayas, and Aztecs of Mesoamerica, and the Incas in South America-established strong governing institutions to rule over their large populations. The cultural evolution toward a more centralized political system was made possible by increased agricultural production, which in turn encouraged population growth, the development of large urban centers, the expansion of regional trade, and the elaboration of governing and social institutions. Despite being isolated from the developments taking place in other parts of the world, the evolution of American civilizations followed a similar pattern as that of other civilizations in Eurasia and Africa. Still, by the fifteenth century the Amerindian empires had not developed sophisticated military weapons, nor had their religions advanced very far from their animist roots-the ritual sacrifice of humans continued in the Aztec Empire up to the Spanish conquest in the early sixteenth century.

In North America, a different pattern of cultural development took place. Scattered across a broad continent, Amerindian tribes in the north formed smaller, self-sustaining civilizations. The transition from food-gathering to food-producing economies among some of the northern peoples did not result in the formation of large empires, as had occurred in Central and South America. There was great variety among the Amerindian societies in the north, from the Mesolithic cultures of the Inuit and Aleuts in the far Northwest, to the more sophisticated Iroquois confederation in the Northeast. Whatever their level of cultural development, all of the Amerindian societies in the Western Hemisphere were affected by European penetration after 1500.