In 2006 the Smithsonian Archives of American Art began digitizing all the Jackson Pollock and Lee Krasner papers, photographs and ephemera in the archives. Now that the 15,096-image collection is available online, I can't tear myself away.
According to the Smithsonian Archives website, the papers measure 15.6 linear feet and date from circa 1914 to 1984, with the bulk of the material dating from 1942 to 1984. The collection documents their personal and professional lives, as well as the legacy of Jackson Pollock's work after his death. Found are biographical material, correspondence, writings by Krasner and others, research material, business and financial records, printed material, scrapbooks, artwork by others, photographs, interview transcripts, audio and video recordings, and motion picture film.
The collection is divided into two series, the first of which focuses on Pollock and includes his scattered papers dating from circa 1914 to his death in 1956, as well as Krasner's papers dating from his death to 1984 about managing Pollock's legacy. This series includes biographical materials, including transcripts and audio recordings of an interview with William Wright in 1949; Pollock's and Krasner's correspondence with Thomas Hart Benton, Betty Parsons Gallery, Bill Davis, B. H. Friedman, Reginald Isaacs, Sidney Janis, Violet De Lazlo, Martha Jackson Gallery, Alfonso Ossorio, Tony Smith, and Clyfford Still, and with one another; Krasner's correspondence concerning Pollock's estate and artwork after his death; numerous writings about Pollock, including an original draft of Bryan Robertson's biography and an essay by Clement Greenberg.
(16 Miles of String is responsible for turning me on to this.)