Robert Frank, one of the most influential photographers of the 20th century, whose visually raw and personally expressive style was pivotal in changing the course of documentary photography, died on Monday in Inverness, Nova Scotia. He was 94.

His death, at Inverness Consolidated Memorial Hospital on Cape Breton Island, was confirmed by Peter MacGill, whose Pace-MacGill Gallery in Manhattan has represented Mr. Frank’s work since 1983. Mr. Frank, a Manhattan resident, had long had a summer home in Mabou, on Cape Breton Island.

Born in Switzerland, Mr. Frank emigrated to New York at the age of 23 as an artistic refugee from what he considered to be the small-minded values of his native country. He was best known for his groundbreaking book, “The Americans,” a masterwork of black and white photographs drawn from his cross-country road trips in the mid-1950s and published in 1959.

[Read our appraisal describing how Robert Frank redefined the expressive potential of documentary photography — until he gave it up.]