This study has determined the historical significance of the James A. Allison Estate as a designed historic landscape and suggested possible guidelines for future development at the site by the current owners, Marian College. Historical evidence indicated that the James A. Allison Estate was designed by noted landscape architect Jens Jensen of Chicago. This was proven through the identification of definable design elements utilized by Jensen in his design work. These included: reliance on native plants, manipulation of space, light and shadow, architectural features (pergolas and bridges), water features, a meadow, and a player's green and formal gardens. National Register Bulletin #18 was then used to determine that the James A. Allison estate could be classified as a designed historic landscape. Suggestions for the future treatment of the site, including guidelines for development, were then created.