History: The Great Depression By Dorothea Lange, 1939-1943, United States

Lange's best-known picture is titled "Migrant Mother." The woman in the photo is Florence Owens Thompson. The original photo featured Florence's thumb and index finger on the tent pole, but the image was later retouched 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:
I saw and approached the hungry and desperate mother, as if drawn by a magnet. I do not remember how I explained my presence or my camera to her, but I do remember she asked me no questions. I made five exposures, working closer and closer from the same direction. I did not ask her name or her history. She told me her age, that she was thirty-two. She said that they had been living on frozen vegetables from the surrounding fields, and birds that the children killed. She had just sold the tires from her car to buy food. There she sat in that lean-to tent with her children huddled around her, and seemed to know that my pictures might help her, and so she helped me. There was a sort of equality about it.
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.