A general overview of the war, supplanted with a bunch of relevant civil-war era maps.
My problem is this should have been a large-format book; the maps looked cool from what I could see of them, but to really get into the detail that would make them fascinating (read notes, details), you'd have to use a magnifying glass, at least in this roughly 8"x10" hardcover.
And the analysis of the maps was limited to a tacked-on paragraph or two at the end of each chapter, so the tie-ins to the chapter material were thin at best.