As a retired Archaeologist I found 1491 to be a readable synthesis of what Archaeologists and Geographers have talked about for a long time. Humans have been in the Americas for over 20,000 years (as recent, long suppressed, publications by Tom Dillehay and Mike Adovoso have proven). We knew much of this 20 or more years ago, and I am glad that someone finally wrote a readable book about it.