Peter Pershan put together this collection of links to a selection of both historically important and contemporary photographers.
Obviously this choice is personal; however,it highlights many of the important contributions to photography.
John_Szarkowski: Link
Historical Photographers
William Henry Fox Talbot (1800-1877):Link
Anna Atkins 1861: Link
Nicephore Niecpce: 1833: Link
Hippolyte Bayard: 1887: Link
Carol Szathmari (1812-1887): Link
Timothy H. O'Sullivan 1840-1882: Link
Mathew Brady (1823-1896): Link1 and more Photos Link
Augste-Rosalie Bisson (1826-1900) & Louis-Auguste Bisson (1814-1876), "Bisson Frères” Photos Link
Nadar (1820-1910): Link
Jacob August Riis (1849-1914): Link and Photos Link
Nagy (1895-1946): Link
Ansel Adams (1902-1984): Link and Photos Link
Alfred Stieglitz(1864-1946): Link and Photos Link
Imogen Cunningham(1883-1976): Link
Edward Weston(1886-1958): Link and Link
Dorothea Lange(1895-1965): Link and Link
Margret Bourke White (1904-1971): Link
Diane Arbus (1923-1971): Link
Edward Steichen (1879-1973): Link
Berenice Abbott (1898-1991):Link
Alfred Eisenstaedt (1898-1995):Link
Yousuf Karsh (1908-2002): >Link
Henri Cartier-Bresson (1908-2004): >Link
Contemporary Photographers
Carl van Vechten: Link
Anthony Cotsifas: Link
Arlene Gottgried: Link
Guillermo Srodek-Hart: Link
Harry Gruyaert: Link
Eve Arnold: Link
Vivian Maier: Link
Lois Conner: Link
Editta Sherman: Link
Louis Stettner: Link
Anthony Hernandez: Link
Gordon Parks: Link
Alexandra de Steiguer: Link
Others
Edwin Land Inventor of Polaroid : Link
Lincoln Kirstein: Link
Group f/64: Link
Mary Street Alinder (Live Video re Group f.64) : Link
A site listing some portrait photogaphers: Link