Poised in a state of perfect equilibrium, the young man with the bike is going nowhere. To explain his predicament and his dejected air, just look at his location. He is standing in Queens, across the river from Manhattan; although the Queensboro Bridge connects the factories and taxi garages of Long Island City with the penthouses and roof gardens of the Upper East Side, he remains stranded in what snooty Manhattanites call “the outer boroughs”.

In the hazy distance, the skyscrapers of midtown Manhattan are out of reach and almost out of sight. Under the bridge’s anchorage there is another barrier – the ruins of the asylums, quarantine hospitals and penitentiaries on Roosevelt Island, a sliver of rock in the East River where New York once confined those it considered insane, infectious or unrespectable. In the 1920s Mae West was briefly locked up there as punishment for being too sexy (though she revenged herself by romancing the prison warden). Half a century after Evelyn Hofer took the photograph, the exclusion zone has widened. That grassy verge has been privatised: the Queens shoreline is now occupied by a glazed rampart of forbiddingly expensive apartment towers. Roosevelt Island too is a dormitory for the rich, with a park that ironically commemorates the American freedoms extolled by President Franklin D Roosevelt – elusive ideals, still not available to all.

Hofer’s subject is pausing to consider his options. Maybe, once the shutter clicked, he rode meekly home to the hinterland. But notice his head-band, favoured by urban guerrillas in the incendiary 1960s: did he stand his ground, shake his fist at the unattainable citadel, and mutter “Burn, baby, burn”?

Evelyn Hofer: New York is published by Steidl, £40