I really enjoyed searching through TEVA and the NPL digital collections. The above photo is a mountain string band from Gatlinburg in 1939. I chose this photo mainly because I enjoy old hillbilly music.
The TEVA site reminded me of some of the collections in American Memory from the Library of Congress. One in particular is the Farm Security Administration - Office of War Information collection, which is an excellent source for photos from the great depression. Here's a direct link to the site http://memory.loc.gov/ammem/fsowhome.html. American Memory is very useful for researchers and it's free.