In 1882, three eminent Victorians attempted to conquer America. One was a Channel Islander who had lost favour with her lover, the Prince of Wales, after dropping ice cream down his neck. The second was a seven-ton Sudanese who received 700 emotional letters on his departure, many enclosing buns. The third was a young Irish poet whose lectures on interior design and Gothic art formed an elaborate publicity stunt for a Gilbert and Sullivan operetta. All three have a claim on the cultural memory, but only one has guest-starred on The Simpsons.

Lillie Langtry played to full houses, but failed to convince anyone she was an actor; Jumbo the elephant was killed by a freight train and cut into profitable chunks by PT Barnum. Oscar Wilde made landfall an object of sceptical curiosity – a specimen of British aestheticism, shipped first-class across the Atlantic to cue up the punchlines of Patience. He paid obeisance to Langtry, denied being offered £200 to ride Jumbo down Broadway with a sunflower in his hand, and emerged in better condition than either. America was where Oscar Wilde became Oscar Wilde.

He arrived with his most celebrated aphorism: "I have nothing to declare but my genius." Say it today on passing through customs, and they'd shred your suitcase and snap on the surgical gloves. Roy Morris's account of Wilde's 260-day, 1,500-mile and 140-gig tour contains comparable scenes of humiliation. In Boston, 60 Harvard students minced down the aisle in black stockings and shoulder-length wigs. In Racine, Wisconsin, the thin, sniggering audience defeated him: Wilde cut short his lecture and went off for a fag. In Leadville, Colorado, however, he was a surprise hit with the miners, who lowered him down No 3 shaft in a rubber overall and plied him with whiskey cocktails. "I brilliantly performed, amidst unanimous applause," he crowed. Declaring His Genius, unfortunately, merits no such response.

Morris is the editor of Military Heritage magazine. As you read his account of Wilde's campaign, it's easy to imagine the author using a croupier's rake to push a little Oscar across a map of the continent. Skirmish after skirmish is reported; background notes on the combatants are supplied, some untested for relevance; fact after fact is logged, and anything that looks too much like an idea is briskly avoided.

He reproduces, for instance, a Washington Post cartoon comparing his subject to a simian figure identified as the Wild Man of Borneo. Oscar holds a sunflower, the monkey a coconut. "If Mr Darwin is right in his theory," the accompanying piece asks, "has not the climax of evolution been reached and are we not heading down the hill toward the aboriginal starting point again?" Wilde's agent complained. The paper printed an apology – to "the Borneo chap" as well as to Oscar. Morris is content to write this up as a funny story about how the press became increasingly inclined to laugh at Wilde, rather than with him. But the raw materials are here for something more interesting.

The Wild Men of Borneo, Waino and Plutano, were small, wiry Ohio farm boys who, by 1882, were among Barnum's most popular clients. They were exhibited as evolutionary throwbacks: "If you examine their little fingers," claimed the publicity, "you will find that conformation such as to afford them astonishing prehensile power." The cartoon juxtaposition speaks volumes about how America viewed Wilde. He is part of an economy of spectacle – an exotic exhibit – but he is also assigned a role in a broader narrative about white racial degeneration, in which his effeminacy is read as a worrying symptom. Yet Morris has no time to stop: he must charge on to his next vignette. This is the only academic book I know that would have worked better as a series of PG Tips cards.

It's the combination of digression and disengagement that puzzles the most. There are two pages on the fire that swept Chicago a decade before Wilde's arrival. There's half a page on what Stanislavski and Henry James thought of a great tragedian whose performance at the Park theatre, New York, was disrupted by Wilde's late arrival. There is no space, though, to mention that the theatre burned down shortly after, on the night Langtry was due to use it for her US debut, and that Wilde's apparent verdict on the inferno ("What a beautiful fire!") was so widely reported that it became the subject of a poem in the Pall Mall Gazette. ("He bade them observe how consummately precious / The glow that suffused the crepuscular sky. / He adjured them to note how unspeakably gracious / The ribands of flame that were waving on high.")

Other entertaining bits of contemporary doggerel do feature, but Morris isn't here for close reading. We're told a satirical poet in Chicago asserted that Wilde had "brains like April butter" – "whatever that meant," shrugs Morris. If a writer takes this attitude, he has to be sure he is in the presence of the genuinely obscure. The poem bursts with allusions to sunflowers, lilies and pansies. Spring grazing gives raw cow's milk a flowery taste. As Morris notes in his first chapter, "Do you really eat flowers for breakfast?" was one of the questions most asked of Wilde.

Like a Dilly Boy trolling the pavement outside Swan and Edgar, Wilde will entertain any plausible suggestion. Terry Eagleton canonised him for Irish Republicanism. For Gyles Brandreth he turned detective. Michael Bracewell hailed him as a 19th-century rock star. Perhaps Morris intended to liberate him from this kind of appropriation, but I suspect no such freedom exists. Wilde remains with us not because he can bear interpretation, but because he is constituted by it – and the best examples read like extensions of his own project. When faced with a biographer who is so disinclined to analyse and so bafflingly incurious, he evaporates.

The cover of the book is sunflower yellow. The endpapers are as orange as Flaming June. The pages are glossy and ordered. But the text fails to live up to them. It has nothing to declare.

• Matthew Sweet's The West End Front is published by Faber.