The origins of the first Americans are still hotly debated in some circles, but the most widely accepted theory is that Asia’s population expanded into North America over the Bering Strait land bridge between 40,000 and 10,000 b.c.e. These Paleo-Indians relied on big game hunting, as well as gathering, and they probably lived more or less as equals in small bands that ranged over large areas. By 8000 b.c.e., however, many large game animals including mastodons, mammoths, and camels had become extinct. Archaeologists debate whether climatic changes or overhunting brought about their demise. The habitable portion of North America contained perhaps 100,000 people during this period; it seems unlikely that such a small, dispersed population could hunt several species to extinction. (Of course, European Americans brought the passenger pigeon to extinction rapidly by repeatedly killing off the youngest generation.)
By 8000 b.c.e., glacial ice was also no longer a factor for most of North America, and many of the landscape’s present-day physical features and animals were in place. Paleo-Indians began to hunt smaller, less mobile creatures, such forest-dwelling deer or fish that repeatedly migrated to the same place. Paleo-Indian population and population density rose dramatically during this period (sometimes referred to as the Archaic period). People living in the Mississippi watershed also began to plant crops such as squash at roughly this time. Eventually, large, sophisticated societies grew from these humble beginnings.
The Mississippian culture, with major cities at Cahokia (near present-day East St. Louis), Spiro, and Natchez, dominated the eastern half of North America. By 1100 c.e., Cahokia was home to a complex, stratified society of 20,000 people. In the Southwest, by roughly 1250, a group called the Anasazi had planned and constructed twelve large towns and hundreds more informal villages, constituting a formidable trading empire.
From 1400 to 1600, these large, centralized societies declined and smaller, decentralized polities, often multiethnic and multilingual, replaced them. These are the forerunners of the Native American communities that met Europeans in the fifteenth and sixteenth centuries. Native American societies were strikingly diverse, speaking hundreds of mutually unintelligible languages, subscribing to widely varying belief systems, and inhabiting virtually every part of North America’s plains, forests, deserts, mountains, and grasslands. They are often divided into broad language groups like Algonquian, Iroquoian, Muskogean, and Siouan; many modern tribal names date from the period of European colonization.
It is important to recognize that Native Americans were undergoing drastic cultural shifts in the period leading up to their discovery by Europeans. One of the most common mistakes in colonial history is to assume that native societies were static, simply waiting for Europeans to enter their land so that history could begin.