The Postal Services is always issuing commemorative and. special edition stamps. Back in 2002 the United States Postal Service introduced some stamps that had some appeal to photographers. It was called the Masters of American Photography.
The photographers are mostly Documentary and Fine Art photographers. Included are the following: Albert Southworth and Josiah Hawes, Timothy O'Sullivan, Carleton Watkins, Gertrude Kasebier, Lewis Hine, Alvin Langdon Coburn, Edward Steichen, Alfred Stieglitz, Man Ray, Edward Weston, James VanDerZee, Dorothea Lange, Walker Evans, W. Eugene Smith, Paul Strand, Ansel Adams, Imogen Cunningham, Andre Kertesz, Garry Winogrand, and Minor White.
Pretty impressive list. Although he is not American I would have include Robert Frank because of his work "The Americans".