William Tecumseh Sherman is one of the most important and controversial generals in American history. Just about the only thing everyone would agree on is his effectiveness. While he's lauded as a Union war hero during the Civil War and a forerunner of modern warfare, the South despised him for his heavy-handed tactics, particularly the burning of Columbia and his March to the Sea.
The hard-hitting Sherman was just as tough in his memoirs, and he also wrote down recollections of when he was stationed in California in the wake of the Mexican-American War. Sherman's work is invaluable not just because of who the author was but because he witnessed the California Gold Rush firsthand.