Yale University has launched a digital database called Photogrammar to map more than 170,000 photographs shot in America during the Great Depression and the Second World War. Under the initiative, which ran from 1935 to 1944, the US Farm Security Administration and Office of War Information paid photographers such as Dorothea Lange, Walker Evans, Jack Delano, Arthur Rothstein and Marjory Collins to document the impact of the declining economy in an effort to galvanise support for agricultural government assistance programmes. The physical negatives, prints, and transparencies are housed in the Library of Congress in Washington, DC.