The Constance Frick Irwin papers date from 1918 to 1995 and measure 12 linear feet. The papers are arranged in six series: Biographical information, Librarianship, Writings, United States WAVES, Photographs, and Artifacts.

The Biographical information series (1921-1995) provides insight into Irwin's interests apart from her professional work. One of her interests was ceramics. She helped found the Hoosier Craft Guild (Box 1: Biographical information, Clubs and organizations, Hoosier Craft Guild). Irwin's autobiographical sketches tell of the importance of her family and education in shaping the writer she became. Irwin's personal correspondence comprises the bulk of this series, containing mostly family letters in the earlier years and fan mail from her readers in the 1960s and 1970s.

The Librarianship series (1934-1967) documents Irwin's work as a high school librarian in Indiana and her professorship at the State University of Iowa Library School.

The Writings series (1927-1991) is the largest series in the collection. The series contains Irwin's lifetime of literary works. She wrote for both children and adults. The topics ranged from legends to the news of the day. In addition to manuscripts the series includes correspondence.

The United States WAVES series (1942-1954) chronicles Irwin's life in the Navy during World War II. The correspondence with family and friends provides a personal view of the period. Stationed in Washington, D.C., Irwin was an eyewitness to life in the capital. Her vivid descriptions in letters to her parents are full of sights and sounds of Washington during the war years.

The Photographs series (1918-1970) contains portraits and snapshots of Irwin from childhood through adulthood and pictures from her travels to New York, Mexico and Europe.

The Artifacts include a WAVES hat and numerous small pins, medals, and awards Irwin received.