Pre-columbian history of North America is shrouded in mystery. The Europeans killed over 90% of the inhabitants and destroyed most of their civilization. They forced the Native Americans off their land, exhiling they few they didn't slaughter to reservations west of the Mississippi. They plowed up the massive earth mounds and tore down sophisticated stone structures to build their own homes, walls, and roads.
There are only a few mounds remaining, such as the massive structure at Cahokia.
Several structures were documented in the 1800s, however, and we can locate many of these, even though they've been turned into golf courses, housing tracts, and farms.
Pre-columbian Indians were not merely nomadic tribes, wandering from place to place. They had permanent homes and communities, sophisticated trading networks, and unique cultural identities. They were spread throughout North America, but the highest population densities were in the Midwestern United States. This map shows a few of the thousands of such communities and structures. Most have been long since destroyed by the European settlers.
Readers are constantly asking me what is being done to research the ancient civilizations discussed in the book. Fortunately, the few remaining sites have been protected as national or state parks, conservation districts, etc. The National Park Service has some excellent material available:
There are many individuals and groups engaged with ongoing research on the many sites of the Adena, Hopewell, and other pre-Columbian civilizations in North America.
Here is one doing some fine work:
Sadly, too few people are aware of the extent and sophistication of the ancient civilizations we live among, particularly in the Midwestern United States. I encourage my readers to visit these sites and contribute to their preservation.
Numerous books and research papers have been written. Here are a few that I recommend: