The book is written by Allan W. Eckert, an Ohio author. He has written a lot of books on a wide variety of subjects. That Dark and Bloody River is one of more recent of his - first published in 1995. Eckert wrote a series of books beginning in late 1960's called the Winning of America series. Bloody River seems to me to be an extention of information in that series. Technically, to answer your question, Eckert's books are considered fiction. However, his books are heavily footnoted and cross referenced and all have what he calls "Amplification Notes". These really make his books come to life. Often these notes are very concise modern day directions to where a particular event took place. His books are considered fiction only because it is not a dry narrative of previously written information or research. He takes his extensive knowledge of history, combines it with research and writes a story that is factually correct in timeline, characters and their actions. Eckert takes his license with dialogue and makes his historical narratives readable. You read the entire Winning of America series and you will be well versed in much of the U.S. struggles thru the Blackhawk wars.