The Secret War for the Union: The Untold Story of Military Intelligence in the Civil WarMost histories of the Civil War explain victory and defeat in terms of the skill of commanders and their troops. Intelligence records disappeared after the war, and thus a critically important element has largely been ignored. Fishel has unearthed substantial collections of such records, and his intelligence explanation radically alters history's understanding of the campaigns. The Secret War for the Union is one of the most important Civil War works