"[2] His major photo essays include World War II photographs, the visual stories of an American country doctor and a nurse midwife, the clinic of Albert Schweitzer in French Equatorial Africa, the city of Pittsburgh, and the pollution which damaged the health of the residents of Minamata in Japan.

[5] On July 25, 1934, The New York Times published a photo by Smith of the Arkansas River dried up into a plate of mud, evidence of the extreme weather events that were devastating the Midwest.

[7] Smith began to work for Life magazine in 1939, quickly building a strong relationship with then picture editor Wilson Hicks.

He was with the American forces during their island-hopping offensive against Japan, photographing U.S. Marines and Japanese prisoners of war at Saipan, Guam, Iwo Jima, and Okinawa.

[13] Between 1948 and 1954 Smith photographed for Life magazine a series of photo essays with a humanist perspective which laid the basis of modern photojournalism, and which were, in the estimate of Encyclopædia Britannica, "characterized by a strong sense of empathy and social conscience.

"[14] In August 1948 Smith photographed Dr. Ernest Ceriani in the town of Kremmling, Colorado, for several weeks, covering the doctor's arduous work in a thinly populated western environment, grappling with life and death situations.

[2] In late 1949, Smith was sent to the UK to cover the General Election, when the Labour Party, under Clement Attlee, was re-elected with a tiny majority.

[17][18] From Wales, Smith travelled to Spain where he spent a month in 1950, photographing the village of Deleitosa, Extremadura, focusing on themes of rural poverty.

[16] Smith attracted the suspicion of the local Guardia Civil, until he finally made an abrupt exit across the border to France.

[19] In 1951, Smith persuaded Life editor Edward Thompson to let him do a photo-journalistic profile of Maude E. Callen, a black nurse midwife working in rural South Carolina.

It was well received and resulted in thousands of dollars in donations to create the Maude Callen Clinic, which opened in Pineville, South Carolina in May 1953, with Smith present at the ceremony.

[25] In 1957, Smith left his wife Carmen and their four children in Croton-on-Hudson and moved into a loft space at 821 Sixth Avenue in Midtown Manhattan which he shared with David X.

[26][27] Smith laid down an intricate network of microphones and obsessively took photographs and recorded jazz musicians playing in the loft space, including Thelonious Monk, Zoot Sims and Rahsaan Roland Kirk.

From 1957 to 1965, Smith made approximately 4,000 hours of recordings on 1,740 reel-to-reel tapes[26] and nearly 40,000 photographs in the loft building in Manhattan's wholesale flower district.

Between September 1971 and October 1974, they rented a house in Minamata, both a fishing village and a "one company" industrial city in Kumamoto Prefecture, Japan.

[30] In January 1972, Smith accompanied activists who were meeting representatives of the Chisso trade unionists at Chiba, to ask why union workers were used by the company as bodyguards.

The group was attacked by Chisso Company employees and members of the union local who beat Smith up, badly damaging his eyesight.

Its centerpiece photograph and one of his most famous works, Tomoko and Mother in the Bath, taken in December 1971, drew worldwide attention to the effects of Minamata disease.

On December 23, 1977, Smith suffered a massive stroke, but made a partial recovery and continued to teach and organize his archive.

"[39]Writing in The Guardian in 2017, Sean O'Hagan described Smith as "perhaps the single most important American photographer in the development of the editorial photo essay.

He was an exacting printer, and the combination of innovation, integrity, and technical mastery in his photography made his work the standard by which photojournalism was measured for many years.