I ordered the book, thank you! As evidence of the paucity of historical knowledge of the Indian peoples, estimates of the pre-Columbian population vary from 10

I ordered the book, thank you! As evidence of the paucity of historical knowledge of the Indian peoples, estimates of the pre-Columbian population vary from 10 million to 100 million. I know about the various rock paintings with symbols, but there isn't enough of that to represent much of anything.