The Historic American Buildings Survey (HABS), the Historic American Engineering Record (HAER), and the Historic American Landscapes Survey (HALS) are parts of the Prints and Photographs Division of the Library of Congress. The collection has been administered since 1933 through cooperative agreements with the NPS, the Library of Congress, and the private sector. Ongoing programs of the NPS have recorded America's built environment in multiformat surveys comprising more than 556,900 measured drawings, large-format photographs, and written histories for more than 38,600 historic structures and sites dating from Pre-Columbian times to the twentieth century. the online presentation of the collections include digitized images of measured drawings, black-and-white photographs, color transparencies, photo captions, data pages including written histories, and supplemental materials.