Read about Mr Fleming and his Southern sympathies and solid historical credentials here.
This book is really boring. The story of actual violence breaking out in Louisiana between two separate governments claiming legitimacy was new to meet (start here). But it's tough to make a story interesting by quoting testimony and not adding any narrative.
I think there are much more interesting and readable books on reconstruction. Mr Fleming's book is still helpful in shedding some light on the period. Read the first couple sections on Union Leagues and then compare the primary, contemporary sources which report on the League's activities to today's Wikipedia entry. Doing so should give you a good idea of the problems associated with the modern, official view of the history of reconstruction.