I like to visit the Library of Congress on occasion for inspiration. Here are a couple of links and some images to get you started. The pictures below are from the Farm Security Administration/Office of War Information, and were captured between 1939 and 1943 throughout the United States.
Jack Delano, Walker Evans, Dorthea Lange, Sheldon Dick, Russell Lee, Gordon Parks, Arthur Rothstein, John Vachon, and Marion Post Wolcott all shot for the Farm Security. Now go, Get Lost!