A History of Photography  
   Contains an extensive history, from earliest times to the 1920s. Includes biographical information on all significant photographers.
   http://www.rleggat.com/photohistory/

History of Photography Timeline  
   Highlights major developments in timeline format.
   http://www.photo.net/history/timeline

Bob's Photo Page  
   Contains a brief history of photography and how film works, profiles the development of modern photography, and has short biographies of early photographers.
   http://home.globalcrossing.net/~sos/photopage.html

George Eastman House Collections  
   Collection includes thousands of photographs and negatives dating from the invention of photography to the present day including many milestones and covering most photographic processes.
   http://www.eastmanhouse.org/inc/collections/photography.asp