The Mary Morton Ellsworth papers date from 1833 to 2004 and measure 2.25 linear feet. The collection consists primarily of personal materials relating to Ellsworth's children, family, and friends. It includes an extensive collection of Christmas cards received by Ellsworth over a period of fifty-five years; some cards have notes, letters, or photographs enclosed. The collection also contains Christmas cards sent by Ellsworth, which include an annual letter describing family events. The newspaper clippings include wedding announcements of family members, and the folder on Jonnifer Ellsworth contains papers she wrote in high school. The genealogy folder includes transcriptions of approximately fifteen letters written by Ellsworth's mother's ancestors in the mid-nineteenth century.

The professional materials in the collection consist mainly of several academic papers written by Ellsworth. These include a paper she wrote during her senior year at Ohio Wesleyan University after she was chosen to spend a semester at the Merrill-Palmer Institute in Detroit and her master's thesis. Ellsworth's retirement album includes photographs of many colleagues at the University Counseling Service as well as remembrances of Morton and her work.

The collection includes photographs of Ellsworth's childhood, young adulthood, and years at Oaknoll retirement center, as well as several of the Kirk family, with whom Mary Ellsworth's daughters lived while she recuperated from tuberculosis. A DVD includes home videos of the Ellsworth family Christmas celebrations from the late 1940s to the late 1950s, and footage of the 1956 Veisha parade in Ames, Iowa, and the 1956 Centennial Parade in Des Moines, Iowa.