It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.
The Digital Public Library of America brings together the riches of America’s libraries, archives, and museums, and makes them freely available to the world.
HABS, HAER, and HALS http://www.loc.gov/pictures/collection/hh/
"Historic American Buildings Survey (HABS) and the Historic American Engineering Record (HAER) Historic American Landscapes Survey (HALS)