Are there common links among the Great Depression photos?

I think that one of the common links in the photos from
the Great Depression is the message of sadness that is an indelible part of both their
pixels and the American setting of the time period.  Dorothea Lange captures this in her
work.  The portraits of life during the Great Depression do not shy from showing the
difficulty of life in economic hardships.  At the same time, the photos she takes looks
at this reality from a human point of view.  The facial expressions of her subjects are
not ones that can escape the reality of what surrounds them.  Migrant
Mother is one such work.  Lange wrote that she was "attracted" by the
"hunger" of the subject, and this is something that cannot be overlooked in the
portrait.  The "modern rural community" of Arthur Rothstein's works also captured this
feeling of loss and displacement in the lives of African- Americans during the 1930s. 
This same sense of barren emptiness is present in Walker Evans' capturing
of Gas Station in 1936.  There is a common experience in these
portraits, and in so many photos of the Great Depression, of the sense of despair and
isolating agony that is present during this time
period.

However, it should be noted that many of these
photojournalists sought to display how life is so that individuals would gain a greater
understanding for the plight of their fellow citizens.  In this a powerful condition of
social realism emerges, when the depiction of art seeks to broaden social connection
between individuals in the hopes of transforming reality from what it is into what
should be.