First, forget pretty much everything you were taught in school. The vast majority of it has been debunked in the last few years of research.
Native Americans have been on this continent for at least 15,000 years ago, minimum, based on recent carbon dating of finds in in southern Chile and
Unless you willing to assert that the people who founded this settlement had a map that showed them where to go and how to get there, then the logical
conclusion is that humans have been in the Americas for thousands of years before that, since you hve to allow time for exploration, settlement,
exploitation, growth, expansion, exploration, settlement, exploitation, etc. It generally takes a few generations of growth before an area is crowded
enough to get people to move on into the unknown. Most population models seemed to think the early americans knew exactly where Tierra del Fuego and
the Bahamas were and raced each other to settle them. Laughable, but taken seriously...anything to minimize the time so that the Euros could feel
themselves just the latest wave coming into an "empty land".
There have been several waves of humanity arriving here in several pulses over a very long span of time, following different routes: coastal via the
kelp beds that run from Asia to South America, overland via the "ice-free corridor", perhaps coastal from Europe but that route lacks friendly kelp
beds, more likely a South American-Africa connection via island hopping.
But no discussion of the early populations can begin until you understand what happened about 13K years ago:
Basically, a Tungaska-like event, but bigger, occurred over the Laurentide ice sheet, causing global climate change and floods, but particularly
devasting North America, reducing populations of everything
to extinction or near-extinctions levels. If you look at the reports of the first
Europeans, the civilizations they described were consistent with what you might expect of "survivor civilizations": the focus was on agronomy and
organizational skills, the development of multiple varietals of basic food types that could survive any type of growing condition, democratic
governance, greater emphasis upon cooperation over competition, generally non-genocidal warfare, etc. The non-American civilizations exhibit the
characteristics of a stressed habitiat minus the catastrophic population collapse: fierce competition, concentration of power, hoarding and so on.
Hope this helps.
[edit on 27-1-2009 by apacheman]