@Yvonne Smith - Here is the Link for the map. It is from WikipediA "The historic and modern day American Indian nations believed to have descended from the overarching Mississippian Culture include: the Alabama, Apalachee,Caddo, Chickasaw, Cherokee, Choctaw, Muscogee Creek, Guale, Hitchiti, Houma, Kansa, Missouria, Mobilian, Natchez, Osage, Quapaw, Seminole, Tunica-Biloxi, Yamasee, ..."
The Lost Civilizations of North America "Why don't most Americans, including many historians, know about the highly advanced ancient civilization that existed in the 'Heartland' of North American near the time of Christ? The Lost Civilizations of North America is a powerful new documentary film that explores this question of historical importance to all Americans, but especially those of Native American descent". The Lost Civilizations of North America documentary DVD Trailer
One of the articles that I was reading about Cahokia said that it was as large as London was at that time, and even as large as Rome, which would be one of the oldest cities in the world. If Cahokia was as large as the oldest and largest cities in the Old World, then it could have possibly been the largest city in existance anywhere back in that day. For it to have been that large and equal to cities that we know had been in existance for many years, there were either a whole lot of people that migrated to North America, or (more likely) they had been here for quite some time, and multiplied rapidly. One of the most interesting oldtime theroies that I have read is that at one time, ages ago, there was only one large continent (possibly Atlantis ?) and something happened that caused the continents to break up in to what we have today. If that happened to be true, then it would explain why we have people of similar backgrounds in diverse countries, and on some of the islands. Not only that, we have similar animals and birds in very diverse parts of the planet, and this would explain how that happened as well. Parrots, as an example, are in South America, and also in Africa. Even some of the extinct creatures were found on more than one continent. Anyway, that could also explain why Cahokia was such a large city back before we even knew there were people here other than a few nomadic early tribes.
"Pangaea or Pangea was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from earlier continental units approximately 300 million years ago, and it began to break apart about 175 million years ago. In contrast to the present Earth and its distribution of continental mass, much of Pangaea was in the southern hemisphere and surrounded by a super ocean, Panthalassa. Pangaea was the last supercontinent to have existed and the first to be reconstructed by geologists". Pangaea In 250 million years it might happen again!
New Evidence May Solve Mystery of America's Huge Ancient City Mississippi floods shaped the rise and fall of the prehistoric metropolis known as Cahokia.
Aliens and Predators II: The Mysterious Depopulation of Cahokia "Cahokia digs have shown the city to be a pre-Columbian Ace Hardware, manufacturing hoes and axes with flint blades. They acquired copper from the Great Lakes, mica from the Carolinas, and shells from the Gulf of Mexico. The river was a superhighway for traders".
It was called Pangaea a time in history when the continents as we know it today was formed. Here is a link to an article about Pangaea, that Joe spoke about.
@Krissttina Isobe - Thanks for the link, I like the idea of the shell being "One big heat conveyor belt"! "While the heat formed in the mantle likely comes from the radioactive decay of unstable elements, such as uranium, scientists don't agree on whether there are mini-pockets of heat flow within the mantle, or if the entire shell is one big heat conveyor belt".