Fritz Zimmerman is an unaffiliated scholar with a B. A. in history from Purdue University. His book "The Encyclopedia of Giants in North America" is the result of over 15 years of research that included pouring through over 10,000 historical documents and newspaper archives at one of the country's largest genealogical libraries. 13 years of archaeological fieldwork of exploring over 700 sites and photographing over 200 mound and earthworks in the Ohio Valley resulted in many of the extant giant's tombs to be be photographed for the first time.