Disloyalty in the Confederacy
If you have an honest interest in getting the full story of the Confederacy during the Civil War, then Disloyalty in the Confederacy is a must-have book. Written by Georgia Lee Tatum in the 1930's, she looks into the various Unionist movements and anti-Confederate sentiment that was prevalent in the Confederacy from the beginning to the end of the Civil War.
I'm sure that many Confederate-leaning reenactors and amateur historians will dismiss this book based on its age and dated research, but I say they're ignoring an important part to the story of the South that is all too willingly overruled via Southern myth or willfull ignorance to look at the full facts. As a matter of fact, this book does stand the test of time and is still relevant. As anyone who has done any real research knows, the Confederacy was a tumultuous place, filled with broken promises and heartbreak. It's far from the fantasy one sees painted of Generals Lee and Jackson. It also includes men who became disillusioned of the war, who never turned their backs on the Union, or realized the war was truly a lost cause.
Ms Tatum did a great job of bringing these stories to the surface and organizing them by the states of the Confederacy. You get a better feel for the overall situation within the Confederacy at the time. Be sure though, this book doesn't take sides, and if you read this book, make sure you read the Forward, because it explains Ms Tatum's train of thought while writing the book (or actually, doctoral dissertation).
This is a recommended read at any level.