The Katherine Willson papers date from 1945 to 2017 and measure 8 linear inches. The papers are arranged into one series: Biographical.

The Biographical series (1945-2017) includes various materials, such as certificates, licenses, booklets, and photographs, that pertain to Katherine Willson's academic career at the University of Iowa and her professional career as a pharmacist. This series also includes two diaries: one from the years 1953 to 1957 that describes the daily life of a student at the University of Iowa and of a newly licensed pharmacist in the 1950s, and one from the year 2011 that displays how she dealt with the loss of her husband of nearly sixty years. Additionally, this series includes a memoir written by her mother, Bettie Brookhart, and organized by her daughter, Esther Willson, in 1980. In this memoir, Bettie Brookhart provides some background on her family history, with pictures of relatives included, and goes into detail about growing up at the beginning of the 20th century. This memoir touches upon topics such as at-home childbirths, the social dynamics within a small town during this time, and information pertaining to Choctaw Native Americans, a tribe that Bettie Brookhart's grandfather was a minister for during the mid-to-late-19th century and early 20th century.