Benjamin, Walter. The Work of Art in an Era of Mechanical Reproduction.
Some Web Addresses of Photo Collections
Go to Photos and Prints: an indexed good collection of historical photo collections, from ca. 1840 onwards.
Japanese American Relocation Digital Archives (except Library of Congress) for instance: Ikaru Iwasaki, Dorothea Lange.
Library of Congress: Fenton Crimean War Photographs (Fenton) - 263 photographs by Roger Fenton. 1855. Views of participants, landscapes and equipment.
Library of Congress: National Child Labor Committee Collection (NCLC) - about 500 photographic prints (records being added) 1908-1924. Photographs, primarily by Lewis Hine, focusing on children, showing workers, working and living conditions, and educational settings. Consists of a portion of the images from the collection for which copy photos have been produced.
Alexander, Sandy. "Out On a Limb: The Spatial Politics of Lynching Photography." - c.f. also, James Allen, Without Sanctuary: Lynching Photography in America, 2000.
Walt Whitman Archive, including first edition (1855) "Song of Myself"