James Hearst's correspondence comprises the majority of this series. It contains approximately 1000 incoming and outgoing letters, which are a mix of personal and professional topics and correspondents, such as with Hearst's first and second wives, friends, publishers, discussions about his writing, his employment at the University of Northern Iowa (UNI), and much more.

One of Hearst's most frequent correspondents was UNI president James William Maucker, who often signed off his letters as "Bill." Other notable correspondents include Ferner Nuhn, Bess Streeter Aldrich, Robert Frost, Carl Sandburg, and Jesse Stuart. Also included are letters from United States Vice President H.A. Wallace; one letter from former First Lady Eleanor Roosevelt to Carmelita Hearst (August 21, 1951); and one letter from Randolph Hearst (May 22, 1974). Some of the correspondence is addressed to Carmelita Hearst, James Hearst's first wife, and Meryl Norton Hearst, his second wife. There are also many letters between Hearst and editors, publishers, and presses discussing his work and publications.

There is a name index to most correspondents available in the University Archives and digitally. "T.L.S." means Typed Letter Signed. "A.L.S." means autograph letter signed. This index was updated to include newly-processed material March 2017.Physical copies of the updated index are available by request. A date, a name, or a portion thereof within parentheses () indicates that the information was added on the basis of the processor's knowledge or information from an envelope.