Over the past 75 years, the Library of Congress and the National Park service have recorded and preserved more than 556,900 drawings, photographs and historical notes for more than 38,600 American buildings, industries, engineering works, and landscapes.
The history of the program is described on the Library of Congress' website as having the following timeline:
The Historic American Buildings Survey (HABS) began during the Great Depression in December 1933, when Charles E. Peterson of the National Park Service submitted a proposal for one thousand out-of-work architects to spend ten weeks documenting "America\'s antique buildings." Having operated under various administrative authorities for its first two years, HABS became a permanent program of the National Park Service in July 1934 and was formally authorized by Congress as part of the Historic Sites Act of 1935. The Historic American Engineering Record (HAER) was founded in 1969 to parallel HABS, providing for documentation of engineering works and industrial sites. In October 2000, the Historic American Landscape Survey (HALS) was permanently established to document historic landscapes. The HABS/HAER/HALS collections at the Library of Congress have grown to constitute a unique, valuable, and extensive repository of knowledge about American buildings, industries, engineering works, and landscapes. Today's documentation is produced primarily by students pursuing degrees in architecture and in history, and the HABS, HAER and HALS programs have proven to be an important training ground for several generations of architects, engineers and historians.With over 75 years of material to draw on, the Library of Congress recently began to digitize and host this information online for researches to use through out the world.
As many thousands of the buildings, churches, residences, shops and mills photographed can also be found on the maps within the Historic Map Works collection, it is fitting that we link the two databases to simplify the research process. With this in mind, we are pleased to offer our visitors to access to these important documents in a format complimentary, yet novel accompaniment to the extensive efforts of the Library of Congress and the National Parks Service.
Though initial access to this information will be via simple search or browse functionality, it is out intention to eventually link the images contained within to specific points on our historic maps as well as incorporate the data into our upcoming Historic Earth™ display engine.
Good luck with your research.