Robert Frank, a trailblazing documentary photographer whose raw, piercing style placed him among the 20th century's greats, has died, according to his gallery. He was 94 years old.

The Swiss-born photographer rose to fame with the publication of his landmark book "The Americans," an unflinching look at U.S. society that proved hugely influential.

A spokesperson from the Manhattan gallery Pace/MacGill told AFP that Frank died overnight of natural causes in Inverness, Nova Scotia.

Frank's seminal book – published in France in 1958 and stateside one year later – emerged out of a series of road trips across the United States with his family in the mid-1950s, a journey akin to those made by his friend and writer Jack Kerouac and others from the "Beat Generation."

Eschewing classic photographic techniques, Frank pioneered the snapshot, capturing telling vignettes in black and white as they presented themselves, exploring the realities of everyday people for whom the American Dream rang hollow.

He produced 28,000 images that were boiled down to 83 for the book that rewrote the rules of photojournalism.

As Kerouac wrote in the preface of the U.S. edition, Frank "sucked a sad poem right out of America onto film."

At lunch counters and drive-in movie theaters, on Route 66 and at champagne get-togethers, his gritty, subjective style laid bare a wide range of emotions and relationships, notably racial, that were rarely found in the popular illustrated magazines of the time.

"Those pictures changed the way I looked at myself, others, this country; I learned what it meant to see & to have a point of view," tweeted New Yorker critic Amanda Petrusich upon news of his death. "Rest easy, Robert Frank, & thank you."