We've just added links to over 200 Chicago documents from the Historic American Buildings Survey (HABS) from the Library of Congress. HABS is an ongoing effort to document "achievements in architecture, engineering, and design." It began in 1933 and has been administered jointly by the Library of Congress and the National Park Service. The Library of Congress has digitized photographs, drawings and other data from the project. For more information on the project, visit the HABS page of the American Memory site. An interesting side note: a number of these photographs were taken by famed Chicago photographer and preservationist Richard Nickel.