CERTAINLY ONE OF THE MOST interesting and intriguing phenomena of that enigmatic decade of excesses praised and maligned as the "Roaring 20s" was the rise of mass spectator sports and the induction of sporting heroes into the national pantheon. So illustrious were these heroes that their names became household words throughout America and their every action was monitored by a hero-manufacturing press and an adoring and idolizing public.

The 1920s was a period of frenetic change and bustling activity, when the nation's shift from an agrarian to an urban frame of reference became a hard reality. The lines separating the old from the new and the past from the present were firmly drawn; Americans had to make adjustments to factory production lines, living in city apartments and a business world that devalued individuality. Although all of these changes were accompanied by rampant materialism and indulgent living, there was a craving in this collectivized society for individual expression, that staple commodity of the recent past. The sporting world, on the other hand, remained an arena for pure individual expression, with success or failure depending on individual preparation and performance. So an America starved for individuality turned to athletic personalities for the virtues of the past.

Randy Roberts, a young sports historian, has chosen perhaps the major sports figure of the era for his colorful biography, Jack Dempsey: The Manassa Mauler. Written in a creative and flowing literary style, but with keen attention to detail and judicious analyses of his material, Roberts approaches the heralded heavweight champion as legend and as symbol of his age.

Born near the turn of the century to a family of modest means in Manassa, Colorado, Dempsey advanced to maturity in a world dominated by rough, rugged and unskilled working-class men. He left home at an early age in search of work and adventure, spent time in hobo jungles, rode the rails and accepted any available employment to survive, from washing dishes and scrubbing floors to the harder work of mining coal. It was in the coal-mining towns that Dempsey learned the art of self-defense. In fact, he became so adept pugilistically that he was soon moving from barroom to barroom in the mining camps looking for wagers after boldly anouncing that he could "lick any sonofabtich in the house." In time, he took up fighting as a profession, and in 1919, won the celebrated heavyweight title. Almost at once he was called a superhuman. This brash young fighter had taken the title from Jess Willard, a man more than seven inches and 50 pounds bigger. As far as Americans were concerned, his feat was the equivalent of David defeating Goliath. Bolstered by a well-orchestrated media campaign, Dempsey became a symbol of stability and heroism in the post-Great War period. Writers transformed the young champion from the boy who struggled with poverty and lived the "rough life" into what Americans desperately needed him to be -- a model of clean living, an exemplar of American values, a gentleman from head to heels.

With the championship came instant social elevation. Now all of society stood in line to meet and to socialize with him. Managed by Tommy Kearns and promoted by the legendary Tex Rickard, he made millions as Hollywood took advantage of his popularity and rushed him into a spate of all-American-hero roles in motion pictures. He made another arm-load of money by touring with a circus; crowds turned out in large numbers to see him in the flesh. Dempsey enjoyed it all; he now counted among his friends the elite and the powerful.

Rickard also took advantage of the champion's popularity. He promoted the Dempsey-Luis Firpo fight as a match-up between North America and South America, with the legitimacy of the Monroe Doctrine pending on the outcome. (A veteran of this technique, Rickard in 1910 had promoted the Jack Johnson-Jess Willard match as a fight between the white and black races, with racial superiority at stake.) Dempsey defeated Firpo and national pride soared. Rickard had successfully drawn the nation into the vortex of a highly commercialized sporting event.

Thanks to Dempsey and his backers, boxing was now a million-dollar enterprise. It had its own characters, plots and dramatic tension. Dempsey was invited by President Coolidge to the White House; his visit symbolized the arrival and acceptance of boxing, a sport previously outlawed in most states. Realizing the commercial value of his popularity, Dempsey learned to convert that popularity into money without risking body or title. Between 1919 and 1926 he only defended his title six times.

Roberts, clearly an admirer of his subject, is remarkably even-handed in dealing Dempsey's personal life. Before he became the champion, Dempsey had married a former prostitute, an element of his past it was difficult to sweep under the carpet. Once revealed, it was followed by her accusation that Dempsey had been a draft-dodger during the war. Though evidence that would prove the charge was suppressed, a major journalistic effort was necessary to rehabilitate his public image in the highly nationalistic postwar period.

Roberts squarely faces Dempsey's racism. The champion refused to fight Harry Wills, a black fighter and the perennial No. 1 contender for the crown throughtout Dempsey's reign. He frequently sparred with black fighters while champion, and had fought them often before winning the title, so he had no personal inhibitions about fighting blacks, according to the author. But he was not about to sacrifice his all-American image by allowing anything as un-American as permitting a black person to compete on equal terms with a white person in anything. In the racist '20s, Dempsey had everything to lose and nothing to gain, both commercially and in popularity. This "white-out" of fair competition is the largest blemish on Dempsey's ring career and on his integrity.

This book is essentially a biography of Dempsey's years as champion -- 1919-1926. Roberts' characteristic thoroughness of research diminishes after Dempsey loses the title to Gene Tunney. Jack Dempsey: The Manassa Mauler is a first-rate slice of Americana. It is fresh, witty, entertaining and serious. Both the scholar and the general reader should have room on their shelves for this important contribution.