The photographer was Dorothea Lange.

In early 1935, [...] Lange began to work for the California State Emergency Relief Administration. That summer, the agency was transferred to the RA, which had recently begun a photodocumentary project to draw attention to the plight of the rural poor. (In 1937, the RA would become the Farm Security Administration, or FSA.) Lange worked for the FSA periodically between 1935 and 1939, primarily traveling around California, the Southwest, and the South to document the hardships of migrant farmers who had been driven west by the twin devastations of the Great Depression and the Dust Bowl.

She's the photographer who took the "Migrant Mother" series, some of the most iconic images of the Depression.