Many of the great photographers of the 20th century worked for or through press agencies or were hires by government agencies. Some did so early in their careers, like Ansel Adams, Brassai. Others continued throughout their careers, like Dorothea Lange, Margaret-Bourke White, Robert Capa, W. Eugene Smith.
The prints that were sent out to use for publication by these agencies and actually used for publication have a special attraction that is different from the values of the exhibition or gallery prints made later by many of these photographers. The origin and history of the actual print can add or even enhance the interest in the image itself.
The exhibit is made up of actual vintage examples, sometimes only available in this format, sometimes later printed in larger signed format for the art market.
The backs of these photographs often contain captions (“snipes’) or notations. If they were actually used for a publication there would often be a date stamp. Sometimes they were marked to indicate a cropping of the larger image in the actual use.
Sometimes a given photograph would be printed as a press photograph at different times, and the date of the specific use would be indicated. The earliest version of a press photograph would have more value than later ones, especially if it was close to the date of the event depicted. A good example is the famous Rosenthal photograph of the raising of the flag on Iwo Jima.