RAVE - 1491, New Revelations Of The Americas Before Columbus, by Charles C. Man

Nothing like the 1421 example above. This one reveals that not only were there well-developed civilizations here before Christophe landed (we already know about the Inca and Maya), but those "Indian" empires were preceded by several others going back as far as 15,000 years ago.

That means several things:

1) Whenever and from wherever these earliest settlers landed, most of Northern Europe was iced over, making the Americas the first or second world, not the "New World".

2) The many cities built by the earliest settlers (especially in what are now Peru, Mexico and Brazil) were way bigger than any then current European cities.

3) Lots of other interesting stuff.