In 1971, the Environmental Protection Agency created the DOCUMERICA Project, a program designed to document and catalogue the effects of the EPA in its efforts towards environmental conservation. After six years, the program was shut down, but the end result was a massive archive of images gathered by over 100 freelance photographers from all across America. A large part of these photographs are now housed on the US National Archives' online catalogue (as well as its Flickr page). These are my favorites.