The Correspondence series is divided into three subseries. The first subseries, dated 1896-1966, also the first to be processed, is heavily weighted toward the period when Cramton was a member of Congress and in the period when he served in the Interior Department, roughly from the mid-1920s to 1933. There is a partial index to correspondents appended to this finding aid for the materials in this first portion of the collection. Cramton corresponded with a wide range of important public figures and notable organizations, such as the American Indian Defense Association, the Anti-Saloon League of America, Hiram Johnson, Mordecai Johnson, Michigan governors Kim Sigler and G. Mennen Williams, U.S. Senator Arthur Vandenberg, and conservationist Gifford Pinchot. This first subseries, though largely correspondence, also includes a scattering of other materials such as memoranda and speeches. The second subseries, though it covers much the same period as the first, 1920-1966, was received following Cramton's death, and includes more personal materials, such as letters of appreciation and letters that Cramton chose not to donate when he was alive. The last subseries consists of letters that Cramton exchanged with members of his family, mainly with his son Louis Kay Cramton, with whom he had a close relationship.