An even better book is
Military Memoirs of A Confederate: A Critical Narrative by Porter Alexander. The great thing about this book which sets it apart from his latter work was that he never intended it to be published.
He wrote it for his kids which meant that he held nothing back. He was critical of Lee, Longstreet, and just about everyone else. He swears and speaks like a soldier. It was just a stream of consciousness. Which makes it fascinating. I believe his wife had it published without him knowing about it. It is raw, with no punches pulled.
Military Memoirs of a Confederate is one of the two greatest memoirs coming out of the Civil War. The other is Grant's memoirs.
Fighting for the Confederacy is also good and is worth reading. However, he wrote intending to publish it and it lacks the punch of the earlier book.
https://www.barnesandnoble.com/w/military-memoirs-of-a-confederate-edward-porter-alexander/1100691123