While there is perhaps a province in which the photograph can tell us nothing more than what we see with our own eyes, there is another in which it proves to us how little our eyes permit us to see. ~Dorothea Lange
If you are not familiar with the work of Lange, by all means follow this link. She is most famous for her work documenting migrant workers in the depression. In later years she joined with Ansel Adams in photographing the internees at Manzanar and worked with Pirkle Jones to record the changing California landscape.
This is arguably her most famous work.