The press materials for The First Assassin include a short document on how I came to write the book. It includes this graf:
My fascination with the Civil War began in childhood, when I spent hours studying the battlefield illustrations in Bruce Catton’s popular picture history. At some point, I started reading the words–and today my bookshelves creak beneath the weight of volumes by Catton, David Herbert Donald, Shelby Foote, Margaret Leech, James McPherson, and the other chroniclers of our great national epic.
All of these writers are excellent, but Catton remains my sentimental favorite. I wrote about him here.