The Mildred Wirt Benson papers measure seven linear feet and date from 1875 to 2012. The 1992, 1993, 1995, and 2018 accessions are divided into nine series: Biographical information (1875-2012), Bibliographic material (1964-1992), Correspondence (1927-2005), Fiction writing (1919-1992), Journalism (1927-2002), University of Iowa (1922-2009), Memory Book (1922-1928), Photographs (1915-2000), Artifacts (undated). The papers contain examples of Benson's fiction writing (including the various stages of writing a series book for a syndicate) as well as her newspaper work. Also included is considerable information of a bibliographic nature, relating to the authorship of the Nancy Drew books. There is little material on Benson's childhood apart from photographs and some material in the memory book pertaining to her high school years. The Biographical information series (1875-2012) contains both biographical and autobiographical articles. This series also includes articles about various awards Benson received, information and the writings of both Asa Wirt and George Benson, and obituaries. Also included are draft manuscripts of “Stars and Stones,” a written work about a trip Benson took to Mexico. Included within this series are miscellaneous personal papers kept by Benson such as various magazine subscriptions; articles; rough drafts of articles; and a book of copies of the National Aeronautic Magazine, FLY, from November of 1908 to August of 1909.

The Bibliographic material series (1964-1992) consists of letters, articles, and newspaper clippings pertaining to the authorship of various Stratemeyer Syndicate books. In the 1960s several book collectors independently began to investigate the true identity of Carolyn Keene; by the late 1970s several people had documented Benson as the first Carolyn Keene. But in anticipation of a new edition of the Nancy Drew series the Stratemeyer Syndicate began to put out publicity indicating that owner Harriet Stratemeyer Adams was Carolyn Keene. This series contains a number of articles on the subject, some verifying Benson's authorship and others naming Adams as the writer of the Nancy Drew mysteries. In 1993, the publishers of the Nancy Drew series books, Simon and Schuster and Grosset and Dunlap, officially acknowledged Benson as the writer of the earliest Nancy Drew books under the pseudonym Carolyn Keene.

The Correspondence series (1927-2005) consists of a small amount of correspondence with Dodd, Mead and Co., a letter from Harriet Adams of the Stratemeyer Syndicate, some correspondence with University of Iowa officials, and a large amount of fan mail from the years 1992, 1993, and 1994. Also included are letters to Benson’s daughter, Peggy Wirt.

The Fiction writing series (1919-1992 and undated) includes an unused radio script, manuscripts of the novel "Quarry Ghost," the working plot for one series book and the working copy of another, and copies of Benson's early short stories. Also included are several drafts of the manuscript “Command the Stars,” a work inspired by Benson’s trips to Central America. The Journalism series (1927-2002) includes correspondence and examples of Benson's reporting ranging from a mid-1920s article in the Des Moines Register to several feature articles on aviation and archaeological sites. Also included are columns written by Benson for The Toledo Times in the 1970s and Toledo Blade from the 1980s to early 2000s. There are many newspaper clippings of her column “On the Go,” which ran in The Blade from the 1980s to her death in 2002. Also included is a scrapbook filled with earlier articles she wrote while at the Clinton Herald.



The Memory book series (1922-1928) contains newspaper clippings, programs, a few photographs, and memorabilia dating from Mildred Augustine's high school and college years in Ladora and Iowa City, Iowa.

The Photographs series (1915-2000, undated) includes portraits, images of Benson as a reporter and as a writer, a picture of Mildred Augustine in front of her childhood home in Ladora, a photograph that depicts the aftermath of an airplane fire from 1948, and one photograph that displays a new model of airplane in 1973. Also included are childhood photos of Mildred Augustine and of Asa A. Wirt, as well as albums and scrapbooks focused on family, vacations, and Mildred Augustine’s college years.

The Artifacts series consists of Benson's typewriter and two landscape paintings, both of which were painted by Benson’s mother, Lillian Augustine. The Special Collections Department at the University of Iowa Libraries has extensive holdings of books by Mildred Wirt Benson.