The Gladys Conn papers date from 1868 to 2001 and measure 12.7 linear inches. The papers are arranged in six series: Biographical information, Correspondence, Diaries, Social work, Trailer family album, and Travel scrapbook.

The Biographical Information series (1868-1975) contains a biographical information sheet written by Conn, obituaries, genealogical papers that trace the Trailer ancestry to 13th century France and a "History of Grandfather Trailer's Life." Conn's activities at Atlantic High School are evident in drama programs, clippings and a bound 1927 edition of the newspaper, The Needle, for which she was the editor-in-chief.

The Correspondence series (1908-1968) consists of greeting cards written by Gladys Conn's children, Chris and Meredith, and letters and postcards from her aunt Grace Trailer MacAvoy, her brother William Trailer, and her father Frank Trailer. Included are letters and notes written by Frank Trailer during his courtship with Elma Graves Trailer and later letters home to his wife and children. A series of Christmas cards by Jerome Young, an acquaintance Conn met in Chicago, completes the series.

The Diaries series (1929-1955) contains two bound diaries detailing the active social life of a university student, dated 1929-1932. The diaries for 1947-1949 and 1955 are written in the style of a five-year diary, with each page containing entries for the same date over several years: in these diaries Conn recorded her daily activities as a mother and community member. In entries dated 1941-1942, Conn provides a detailed account of the birth of her son Chris and his early childhood development.

Conn's training and later employment as a social worker in Iowa and Chicago are documented in the Social Work: Education and Employment series (1931-1969). Included are university transcripts and correspondence regarding her course requirements, the Social Service League annual reports dating 1938-1943, and case studies.

The Trailer Family Album series (1908-1975) consists of newspaper clippings, correspondence, and numerous candid and posed images of the Trailer family on their homestead in Marne, Iowa. Inserts include Conn's baby book, her first letter, and wedding, death, and birth announcements. The album was disassembled for preservation purposes.

Conn's trip to Europe with her daughter Meredith in 1961 is detailed in the Travel Scrapbook series (1961-2001). The scrapbook contains printed travel brochures, itineraries, and postcards. Conn's travel notes, photographs, and correspondence with acquaintances made during their travels provide a personal account of the trip. Gladys and Meredith Conn's presentation notes and outlines complete the series.