Four-legged all-American hero diverts nation

Why do American heroes have feet of clay? The sublime Joe DiMaggio, according to a recent biography, was in reality a greedy opportunist. Kobe Bryant, a role-model basketball star, is currently arraigned on rape charges. And even Private Jessica Lynch's dramatic rescue in Iraq seems to have been less than meets the eye.

The lesson is clear: put not your trust in frail humans, but go for a horse instead. And that is what America is doing.

The most intriguing movie here this summer deals not with Spy Kids, Terminators or Pirates in the Caribbean. It is called Seabiscuit.

For us foreigners, the name may not ring a bell. But for Americans of a certain age, it summons up the ultimate feelgood story - the little racehorse whose exploits, briefly at least, banished the miseries of the Depression.

The Americans have always lusted after heroes and lionised bygone eras in the hunt for them. The 1950s - that decade of uptight consumerism - are hailed as an age of innocent purity. The war of the 1940s was the defining moment of "the Greatest Generation". And now the 1930s - a New Deal America hailed by Time magazine as "a lot better than the one we inhabit ... more generous, less noxiously self-centred and confident".

And what better symbol of this splendid age than Seabiscuit? As a sports story this is one of the all-time greats. The film, starring Tobey Maguire and Jeff Bridges, is based on Laura Hillenbrand's book (69 weeks on the best-seller lists) and recounts the career of a scruffy, gutsy little horse from California who is rescued by a canny old trainer from oblivion and turned into a serial winner of major races.

In short order Seabiscuit becomes a poor man's hero, as beloved as FDR himself. He is the equine embodiment of how Americans love to imagine themselves: scrappy underdogs who manage to beat the odds.

The climactic moment of the film is the head-to-head challenge race in 1938 between Seabiscuit and the supposedly invincible War Admiral, winner of the Triple Crown the previous year. This is the little guy against the big guy; a hick and upstart West Coast (ie before LA started getting serious pretensions) against arrogant East Coast bluebloods.

And, of course, Seabiscuit, the 2-1 underdog, won on War Admiral's home track of Pimlico, in Baltimore. The trip back by rail to California was a Roman triumphal progress, with vast crowds greeting the horse at every stop.

The film isn't perfect. It takes itself too seriously. The beginning is ponderous. By splicing in newsreel clips of the 1920s and 1930s, it blurs the line between fact and fiction. It even enlists David McCullough, narrator of weighty public television documentaries on the Civil War and baseball, to do the voice-overs. There are lots of corny lines about second chances, extolling Seabiscuit as "a horse who won't give up, even when life beats him by a nose".

And for all the veneer of historical accuracy, it takes a few liberties with the Seabiscuit story. Nor does it dwell on base rumours that Seabiscuit's prowess might have owed a little to unnatural stimulants.

Basically, however, the story is true, and cannot be gainsaid by the rewriter of history. No human, not even Tom Smith, Seabiscuit's mysterious horse-whisperer of a trainer, can converse with a horse. And if doubts there are, they are banished by the film's fantastic race sequences, of little men perched atop charging, jostling 1,200lb beasts, thundering along at 45mph. This is surely horse-racing as it truly is, not the streaking blur of jockeys' silks from half a mile away that you see at the track itself. When the screen Seabiscuit crushed the mighty War Admiral, the theatre audience burst into applause.

As none other than George Bush will testify, the film is an unbeatable diversion from Iraq, recession, budget deficits and terror alerts. The other evening, the President and First Lady invited Ms Hillenbrand to a private showing of the film at the White House with luminaries such as Steven Spielberg. It was, reportedly, a night to remember. When it was over, the writer recounts, Laura Bush "brought me cookies in the shape of a horse". A horse, moreover, that is an unassailable American hero for the ages.