Joe Louis: Hard Times Man, By Randy Roberts

Martin Luther King was fond of telling a story about a prisoner being executed whose last words as gas seeped into the chamber were: "Save me, Joe Louis!" Apocryphal as it was, it conveyed the Brown Bomber's status as cheerleader of his country's long march out of the Depression and into war against tyranny. As historian Randy Roberts indicates in his introduction to this gripping life and times, sport is often freighted with symbolism. Louis's career represents one of the extreme examples. This is overwhelmingly a book about what Louis signified.

That's not in an abstract, intellectualised way, a mere boxer's shoulders supporting fanciful constructs, but in a manner that actually helped shape the progress of the society that took him to its heart. The "Black Moses", as Time called him, became a lightning-rod for the forces that convulsed the US during the last century.

Along with horse racing and baseball, boxing was one of the US's big three sports – and big three obsessions. As soon as Louis began to cut a swathe through a white-dominated heavyweight division, he became a "road map" of American race relations, coached in and out of the ring to be the antithesis of the swaggering, miscenegating Jack Johnson, the first black heavweight champion of the world, whose reign had done little to assuage whites' basest fears.

Louis's influence would spread beyond racial issues. When he lost in 1936 to the German Max Schmeling (who also hauled round with him a great deal of semiotic baggage), the defeat was interpreted as a sign of America's over-confidence in the wake of the New Deal. But not till the second Schmeling fight, when he battered the Führer's chum into first-round oblivion, did nationality and ideology trump race.

Louis had become all-American, and had even given an inkling, the editorials trumpeted, about how Hitler might be stopped. But if the champion of black America was now champion of all America, for blacks his pre-eminence suggested that perhaps the whole racist edifice was, as Roberts puts it, "a bundle of myths and lies."

Then, as war loomed, Louis became truly iconic. That word is frowned upon by the more fastidious journalists, but here exception must be made. Having campaigned against Roosevelt for the Republicans, he now swung his PR weight behind the war, donating fight purses to a navy relief fund then enlisting, staging more than a hundred exhibition fights for US soldiers.

Those bouts were never, at his insistence, in front of segregated crowds. And behind the scenes he worked quietly to make army life more tolerable for black soldiers (there's an astonishing litany of examples of how badly they were treated). Non-sporting types might suggest he achieved more in this respect than even he did in the ring.

In Roberts' wonderfully lucid exposition of Louis's times, sometimes the man himself seems elusive – as in life. His wedding to his first wife, Marva, is dealt with in a few sentences. But it was squeezed in between a pre-fight nap and a four-round battering of Max Baer. Gradually a picture emerges: he was quiet but with a quick, dry wit, extravagant and recklessly generous with money, incapable of fidelity and allergic to domestic life, taking off for weeks at a time. But he appears only in glimpses. Roberts has a big story to tell, and the tale of Louis the man is sometimes crowded out by history.