BOOK REVIEW : Taking a Hard Look at Myths About America’s Frontier Soul : GUNFIGHTER NATION: The Myth of the Frontier in 20th-Century America , by Richard Slotkin , Atheneum, $40, 850 pages

By 1893, when Frederick Jackson Turner heralded the “closing” of the American frontier, the Old West that we remember from movies and dime novels had ceased to exist. But the myth of the Old West, writes historian and novelist Richard Slotkin, was thriving. To this day, the myth of the frontier continues to shape the way Americans think of themselves and the way America conducts itself in the real world.

In this new book of cultural history on a grand and even audacious scale, Slotkin blazes a trail into the “mythic space” of the frontier. Sprawling across 850 dense but mostly readable pages and a century or so of American history, “Gunfighter Nation” is a kind of monument in itself. But it is also the third volume in a series that reaches back nearly two decades into Slotkin’s career as an interpreter of the American frontier.

“The Myth of the Frontier is our oldest and most characteristic myth,” Slotkin explains, “expressed in a body of literature, folklore, ritual, historiography and polemics produced over three centuries.”

Slotkin is not so simplistic as to suggest that the frontier myth is reflected only in cowboy movies and Zane Grey novels. Rather, “Gunfighter Nation” ranges broadly and imaginatively through high culture and popular culture, geopolitics and electoral politics, and Slotkin points out how the frontier myth is refracted in works as diverse as Dashiell Hammett’s hard-boiled detective stories, Hemingway’s “For Whom the Bell Tolls,” John Wayne’s “The Green Berets,” Martin Scorsese’s “Taxi Driver” and the inaugural address of John F. Kennedy.

Although Slotkin focuses on the frontier myth in pulp fiction, Saturday matinees and other products of what he calls the “commercial culture industries,” he insists that the myth can draw blood in the real world. He shows, for instance, how Custer’s Last Stand, a genuine historical event, was turned into a kind of passion play by such Wild West impresarios as Buffalo Bill Cody.

The symbolic meanings Cody and others helped attach to the Last Stand may have prompted flesh-and-blood atrocities in the form of lynchings, vigilante attacks on labor organizers, and battlefield excesses such as My Lai.

In the iconography of the frontier myth, Slotkin writes, “The savage enemy kills and terrorizes without limit . . . in order to exterminate or drive out the civilized race (and) the civilized race learns to respond in kind. A cycle of massacre and revenge is thus inaugurated that drives both sides toward a war of extermination.”

Indeed, “Gunfighter Nation” emphasizes that the frontier myth was always a ragged and two-edged weapon. For instance, we can discern the rough-and-ready egalitarianism in the “social banditry” of someone like Jesse James, who started out as a figure in dime novels and ended up as a Christlike personage in the hands of folk singer Woody Guthrie.

But, as Slotkin reminds us, the very notion of a “savage war” between the frontiersman and the Indian suggests a racist and even genocidal imperative, and the heroic gunfighter--”an armed redeemer”--can also be seen as a vigilante or, in his contemporary urban incarnation, even a psychopath:

“The world of the urban gunslinger film is cognate to that of the horror and ‘slasher’ film,” Slotkin writes. “These films carry to an extreme the premise of ‘Dirty Harry’ and ‘Death Wish,’ that our world is out of control, pervaded by an evil against which we feel helpless.”

“Gunfighter Nation” is an audacious and demanding but mostly convincing book. The frontier myth, in Slotkin’s hands, is “a vein of latent ideological power,” “a complexly resonant symbol,” a “dialogue with history.”

Through it, Slotkin not only portrays our nation’s history, culture and politics, he gains insight into its soul.