Hadn't heard of that book. Are you getting a lot out of it? The use of excerpts from letters and diaries sounds interesting, but some reviewers (a minority) say it's heavy going and like reading a phone book.
I am loving it. It's 990 pages but it's not heavy going at all, I read it an hour a day at work during my break, so I am only taking in easily digestible chunks at a time. The maps are quite numerous for a history book, (of course being a wargamer I would like even more maps) and work sufficiently well to help understand a battleground and fix it in my head.
I found the book in a charity shop brand new for 50p hadn't even been read.
it's pretty well thumbed now though, it looks like it's been through a war itself.
Interestingly The map of the Chattanooga battle looks very like your game representation, I recognised it instantly, so good job well done!