By far, one of the most riveting novels by this author. Shiloh was a terrible battle by any account, as to fighting conditions and loss of life. This account, in my opinion, far excels The Red Badge of Courage for the portrayal of the awful conditions the fighting troops endured. It reminds me of the genre busting soldiers accounts of Viet Nam when those novels started coming out in the 1980's. This is very good historical fiction, although fiction doesn't quite fit since historians speculate mind sets, attitudes, etc. of historical actors, so it is not much of a stretch to merely animate them further with dialog. I have studied a lot of US History, and this I think really fleshes out the picture. I wish I were more eloquent, but this really makes accurate history accessible and exciting.
Update: I also wanted to mention that while many historians don't spend much time on the western theater, John Keegan in his The American Civil War, makes a very compelling case that the western, which eventually expanded into the southern, south eastern, and finally merged with the eastern theater, was more strategically important since many of the battles in the eastern theater between Washington and Richmond only served to keep large parts of the armies tied up in mostly defensive actions. Lee eventually quit Richmond only after the union armies merged from north and south, and he had nowhere to go but west towards the Shenandoah, and he didn't get very far after that. So Shiloh really was a pivotal loss, and the dominoes started falling from there.