Digital scans of the "Mosaic of Wabash River, Indiana: Terre Haute to Logansport". Taken by the US Army Corps of Engineers, these are the very first aerial photos ever taken for commercial use. For further information, see:
Birdseye, C.H. (1940). "Stereoscopic Phototopographic Mapping". Annals of the Association of American Geographers 30. Page 11. Original print volumes are located in the Humanities, Social Science Library.
The Indiana Geological Survey (IGS) has created the "Indiana Historical Aerial Photo Index" (IHAPI) interactive map to facilitate the identification and retrieval of historical aerial photographs. More than 950 large-format photomosaic index maps in the IGS archive were scanned and georeferenced, and then mosaicked to produce 466 county-based images dating from the 1930s to the 1980s. From these images, a point index was created showing the upper-right corners of 113,035 individual historical aerial photographs. The interactive map allows users to easily locate a site of interest and determine unique identification numbers for individual photos. Copies of the photos can then be ordered from various archival collections, including the IGS archive.