The Magnum photo agency is marking its 70th anniversary with an exhibition that celebrates the Big .

Picture this: Mr James Dean walking through a rain-drenched Times Square, shoulders hunched in his ample overcoat. A llama’s head, also in Times Square, poking through a car window, the lights of Broadway ablaze behind its perky ears. A chihuahua in a bespoke sweater, viewed at pavement level, next to its owner’s chicly shod feet. They’ve all got something in common, besides being classic images of 1950s New York City. They’re all Magnum photos, shot by Mr Dennis Stock, Ms Inge Morath and Mr Elliott Erwitt respectively.

Magnum, the legendary photo agency, is celebrating its 70th anniversary with an exhibition of images captured during its – and, arguably, New York City’s – golden age. It was founded in Paris in 1947 as a co-op by, among others, Mr Robert Capa and Mr Henri Cartier-Bresson, but it soon acquired a New York outpost and a burgeoning membership, including Mr Erwitt, who joined in 1953, at the tender age of 24. “It was a lot like a family,” he tells MR PORTER 64 years later, his gruff, no-nonsense tones echoing the crisp, candid tenor of his images, from Mr Che Guevara in 1960s Cuba to nudists in southeast England in the 1970s. “We all looked out for each other. We gave each other advice. We edited each other’s work.” A beat. “And we did a lot of drinking together.”

An image by Mr Werner Bischof illustrates this. Mr Erwitt, tie askew, sits on a sofa with his wife and baby son in the heart of the Magnum offices on 64th street, amid piles of contact sheets and folders, and secretaries banging away at their Olivettis. An empty magnum of champagne sits on the shelf above them. It was Mr Capa’s favourite drink, and symbolised the joie de vivre and pioneering spirit of the agency’s early years. “People like Cartier-Bresson, Capa and Eve Arnold were great inspirations and wonderful friends,” says Mr Erwitt. “And New York in the Fifties was the place to be. Magazines like Time and Life sent you off on terrific assignments. That whole set-up has now more or less disappeared.”

The photographs in the exhibition – Early Magnum: On & In New York – will be presented simultaneously at the city’s National Arts Club Grand Gallery and on the Magnum website, where they’ll be available to purchase. So, this is your chance to grab a slice of photographic history: Mr Bruce Davidson’s intimate portraits of the youthful, cocky members of a Brooklyn gang, long before the borough became Hipster Central; Ms Arnold’s dynamic backstage shots of a Harlem fashion show; or, indeed, Mr Erwitt’s study of a fashionably dressed woman contemplating the Empire State Building, looming out of the midtown smog. Mr Erwitt still lives in New York, in an eighth-floor apartment facing Central Park, and is still taking pictures. “Magnum has always let me do my thing,” he says. “I don’t do nostalgia, but these images really conjure a time and a place. I’m glad we were all around to lay hold of it.”

Keep up to date with The Daily by signing up to our weekly email roundup. Click here to update your email preferences