resources
Mary Werner Marien : Photography, a Cultural History
http://www.google.com/search?client=safari&rls=en&q=photography+a+cultural+history&ie=UTF-8&oe=UTF-8
Rob Leggat History of Photography
http://www.rleggat.com/photohistory/
National Geographic
http://photography.nationalgeographic.com/photography/photographers/photography-timeline.html
Todd Roeth History of Photography
http://www.toddroeth.com/class/art_256/19/02-history-of-the-camera
The Daguerre Society
http://www.daguerre.org/
The History Channel
http://www.history.com/encyclopedia.do?articleId=219190