Dorothea Lange (1895-1965) has been called America's greatest documentary photographer. She is best known for her chronicles of the Great Depression and for her photographs of migratory farm workers. Below are 42 pre-World War II photographs she created for the U.S. Farm Security Administration (FSA) investigating living conditions of farm workers and their families in Western states such as California. Most of the workers had come west to escape the Dust Bowl, the lengthy drought which devastated millions of acres of farmland in Midwestern states such as Oklahoma.