"When the legend becomes fact, print the legend." This line from director John Ford's film The Man Who Shot Liberty Valance serves as an epigraph for the life of the legendary filmmaker. Through a career that spanned decades and included dozens of films--among them such American masterpieces as The Searchers, The Grapes of Wrath, The Quiet Man, Stagecoach, and How Green Was My Valley--John Ford managed to...