http://historymatters.gmu.edu/mse/Photos/online.htm
This is a good place to see some documentary photography collections.There are a lot of sites on Native Americans. That’s good. But, I find a scarcity of sites relating to Latinos, Mexican Americans or the Border. Do you have to be eliminated to get documented.
While I’m at it, here are a few more documentary sites:
http://www.maryellenmark.com
http://chnm.gmu.edu/fsa/
http://www.soros.org/initiatives/photography/focus_areas/mw/10
http://www.edelmangallery.com/misrach.htm