This thin book is a short but curiously complete description of the Battle of Shiloh in April 1862. It has often been used as a jumping off point for other historians writing about the Civil War, and is only being published recently to the general public.
The author was a veteran of the battle, and worked at the park in the 19th Century collecting other veteran reports to complete this book. It is the kind of thing that nobody can repeat now.
It also comes with some maps of the battle on CD-ROM.
A nice little book, if better limited to the enthusiast than someone starting out.