[1][2] At the time of donation, the collection consisted of 6,500 images by 900 artists, with an estimated value of $65 million.
The collection spans the history of photography, from 1839 to the present, with works by Southworth & Hawes, Carleton Watkins, Timothy O'Sullivan, Alvin Langdon Coburn, Edward Steichen, Alfred Stieglitz, Dorothea Lange, Harry Callahan, Jerry N. Uelsmann, Lee Friedlander, Andy Warhol, and Cindy Sherman.
Hallmark vice president David Strout made the first acquisition of 141 prints by Harry Callahan.
In the next 12-years, bodies of work by major leading photographers, from Edward Weston and Imogen Cunningham to László Moholy-Nagy and Linda Connor were acquired.
To accompany a 2007 exhibition at the Nelson-Atkins Museum, a survey by Davis and Jane L. Aspinwall of the collection's key 19th century contents was published: The Origins of American Photography, 1839-1885, from Daguerreotype to Dry-Plate (2007).