What was the believed native population of the Americans in 1492?

"Estimates of the number of Native Americans in 1492 vary widely -- from eight million to more than one hundred million."

-- American Passages: A History of the United States, Brief Second Edition Answer 2:

There have been two estimates done, 1) by the US Government that estimates 25 Million Native Americans (this study was discounted as highly inaccurate) and 2) By independent researchers that show between 75 and 114 million Native American's.