Cracked.com has a really interesting article up:

6 Ridiculous Lies You Believe About the Founding of America

Central to these is the little reported but apocalyptic plague that struck the Americas right around the time of the post-Columbus European colonization. Most likely this plague was smallpox brought by the Europeans, coupled with some native hemoragic fevers and other diseases from Europe and the Americas. Rather than the Europeans wiping out the Injuns in wars of conquest, the Europeans arrived in lands that had been modified and improved by the natives, and depopulated shortly before the Europeans arrived.

This wasn’t news to me, but the sudden explosive growth of forests in the New World after the death of 90+ percent of the extant population leading to a substantial drawdown in atmospheric CO2 and a resultant mini-ice age was news to me.