The Spanish Civil War (1936-1939) inspired and haunted an extraordinary number of exceptional artists and writers, including Pablo Picasso, Joan Miro, Martha Gellhorn, Ernest Hemingway, George Orwell, and John Dos Passos. The idealism of the cause--defending democracy from fascism at a time when Europe was darkening toward another world war--and the brutality of the conflict drew from them some of their best work: Guernica, For Whom the Bell Tolls,...