"I remember laboring, around 1971, on a screen offering for John Wayne, James Stewart, and Henry Fonda, a bittersweet, end-of-the-West Western, in which no scalps were taken and no victories were won," Larry McMurtry recalled in New Republic. "The three actors were horrified, genuinely and touchingly horrified. Over? The Old West? They couldn't quite articulate it, but what they were struggling to say, I think, in response to the disturbing script that eventually became Lonesome Dove, was that the only point of the movies, and thus, more or less, of their lives, was that the Old West need never be over. You might as well say that America could be over, a notion so high-concept as to be, at the time, unthinkable, or at least unproduceable."

In the years since this unsuccessful effort, however, McMurtry's acclaimed novels and their popular screen adaptations have exposed a large audience to his...