The earliest correspondence in the collection is from her family. Most 1920s and 1930s correspondence is film related and located in Series II., Career, especially in the United Artists subseries. The 1940s are most prominently represented in the Multiprises, Inc. subseries of Series III., Business Interests.
Among the correspondents are: Roy E. Aitken, Michelle Farmer Amon, Kenneth Anger, Robert Balzer, Tallulah Bankhead, Richard Barthelmess, Earl Blackwell, Virginia Bowker, Charles Brackett, Lewis L. Bredin, Harry A. Bruno, Carol Burnett, George Bush, Francis X. Bushman, Richard E. Byrd, Walter Byron, James Cagney, Eddie Cantor, Carol Channing, Maurice Chevalier, Henri Coanda, Ronald Colman, Noel Coward, Fleur Cowles, Joan Crawford, George Cukor, Michael Curtiz, Gloria Daly, Raymond W. Daum, William M. Davey, Marion Davies, Cecil B. DeMille, Indira Devi, Thomas E. Dewey, Theodore Dreiser, William Dufty, Alan Dwan, Nelson Eddy, David Edstrom, Mamie Doud Eisenhower, Harlan Ellison, Douglas Fairbanks, Douglas Fairbanks, Jr., Michael Farmer, José Ferrer, Hy Gardner, George, Duke of Kent, George Gershwin, Margaret Ghika, Lillian Gish, Hubert de Givenchy, Elinor Glyn, Edmund Goulding, Gladys Griffith, Alec Guinness, Edmund Gwenn, Forrest Halsey, Oscar Hammerstein II, Helen Hayes, Edith Head, William Randolph Hearst, Ethel Helmsing, Katharine Hepburn, Conrad Hilton,
Prince Franz Hohenlohe, Bob Hope, Hedda Hopper, Edward Everett Horton, L. Ron Hubbard, René Hubert, William Bradford Huie, George S. Kaufman, Edward Moore Kennedy, Harold J. Kennedy, John F. Kennedy, Joseph P. Kennedy, Rose Fitzgerald Kennedy, Jean Kerr, Ed Koch, Kathryn Kuhlman, Michio Kushi, Henri de La Falaise, Henri Langlois, Beatrice LaPlante, Rod LaRocque, Jesse L. Lasky, Evelyn Laye, Vivien Leigh, Mervyn LeRoy, Clare Boothe Luce, Joel McCrea, Roddy McDowall, Frances Norton Manning,
Arlette Marchal, Stanley Marcus, Frances Marion, Gene Markey, Herbert Marshall, James Michener, Marshall Neilan, David Niven, Richard M. Nixon, Merle Oberon, Laurence Olivier, Louella Parsons, Mary Pickford, ZaSu Pitts, Rosa Ponselle, Harold Prince, Ram Gopal, Ronald Reagan, Ginger Rogers, Eleanor Roosevelt, Adela Rogers St. Johns, Elsa Schiaparelli, Gustave Schirmer, David O. Selznick, Joseph Sharfshin, Eunice Kennedy Shriver, R. Lawrence Siegel, Herbert K. Somborn, Barbara Stanwyck, Edward Steichen, Preston Sturges, Ed Sullivan, Joseph Patrick Swanson, Joseph Theodore Swanson, Bess Truman, Valentina, Erich Von Stroheim, Raoul Walsh, Barbara Walters, LeRoy P. ("Sport") Ward, Clifton Webb, Orson Welles, Dan Werlé, Billy Wilder, Lois Wilson, Walter Winchell, Sam Wood, Adelaide Woodruff, Florenz Ziegfeld, Adolph Zukor, and others.
Among some of the more intriguing pieces of correspondence are: a letter from a twelve year old John F. Kennedy, thanking Miss Swanson for a Christmas present; a signed, self-caricature note from George Gershwin; René Hubert's voluminous, illustrated correspondence; early papers of Herbert K. Somborn's company, Equity Pictures; and a series of mail from Kenneth Anger, which arose from a lawsuit involving his book Hollywood Babylon. There is relatively little correspondence with Joseph P. Kennedy; most of it is found in Series II., Career, and it is generally characterized by business dealings.
Also included is a large group of fan mail, and fans' addresses kept on index cards, with carbons of responses, or notations that photographs or letters were sent, or perhaps a phone call was made.