Dorothea Lange (May 25 1895 - October 11 1965) was an influential American documentary photographer and photojournalist, best known for her Depression-era work for the Farm Security Administration (FSA). Lange's photographs humanized the tragic consequences of the Great Depression and profoundly influenced the development of documentary photography.

Born in Hoboken, New Jersey, her birth name was Dorothea Margarette Nutzhorn. She eventually dropped her middle and last names, adopting her mother's maiden name of Lange. Lange developed polio in 1902, at age 7. Like many other polio victims before treatment was available, Lange emerged with a weakened and wizened right leg and dropped foot. Although she compensated well for her disability, she always limped.

Lange was educated in photography in a class taught by Clarence H. White (in New York City) and informally apprenticed her to several New York photography studios, including that of the famed Arnold Genthe. In 1918, she moved to San Francisco, where she opened a successful portrait studio. She lived across the bay in Berkeley for the rest of her life. In 1920, she married the noted western painter Maynard Dixon, with whom she had two sons: Daniel, born 1925, and John, born 1928.

With the onset of the Great Depression, Lange turned her camera lens from the studio to the street. Her studies of unemployed and homeless people captured the attention of local photographers and led to her employment with the federal Resettlement Administration (RA), later called the Farm Security Administration (FSA).

In December 1935, she divorced Dixon and married agricultural economist Paul Schuster Taylor, Professor of Economics at the University of California, Berkeley. Taylor educated Lange in social and political matters, and together they documented rural poverty and the exploitation of sharecroppers and migrant laborers for the next five years — Taylor interviewing and gathering economic data, Lange taking photos.

From 1935 to 1939, Lange's work for the RA and FSA brought the plight of the poor and forgotten — particularly sharecroppers, displaced farm families, and migrant workers — to public attention. Distributed free to newspapers across the country, her poignant images became icons of the era.

Lange's best-known picture is titled "Migrant Mother". The woman in the photo is Florence Owens Thompson, but Lange apparently never knew her name. The original photo had Florence's thumb and index finger on the tent pole, and was retouched in an attempt to hide Florence's thumb. Her index finger was left untouched (lower right in photo).

In 1960, Lange spoke about her experience taking the photograph: According to Thompson's son, Lange got some details of this story wrong, but the impact of the picture was based on the image showing the strength and need of migrant workers.

In 1941, Lange was awarded a Guggenheim Fellowship for excellence in photography. After the attack on Pearl Harbor, she gave up the prestigious award to record the forced evacuation of Japanese-Americans (Nisei) to relocation camps in the American West, on assignment for the War Relocation Authority (WRA). She covered the rounding up of Japanese Americans, their evacuation into temporary assembly centers, and Manzanar, the first of the permanent internment camps. To many observers, her photograph of young Japanese-American girls pledging allegiance to the flag shortly before they were sent to internment camps is a haunting reminder of this policy of detaining people without charging them with any crime or affording them any appeal.

Her images were so obviously critical that the Army impounded them. Today her photographs of the internment are available in the National Archives on the website of the Still Photographs Division, and at the Bancroft Library of the University of California, Berkeley.

In 1952, Lange co-founded the photographic magazine Aperture. In the last two decades of her life, Lange's health was poor. She suffered from gastric problems, including bleeding ulcers, as well as post-polio syndrome — although this renewal of the pain and weakness of polio was not yet recognized by most physicians. She died of esophageal cancer on October 11, 1965, aged 70.

Lange was survived by her second husband, Paul Taylor, two children, three stepchildren, and numerous grandchildren and great-grandchildren.

In 1972 the Whitney Museum used 27 of Lange's photographs in an exhibit entitled Executive Order 9066. This exhibit highlighted the Japanese Internment during World War 2.