The Institute for the Study of American Cultures, or ISAC, was devoted to the study of pre-Columbian contact between the Old and New Worlds. ISAC was founded by Dr. Joseph B. Mahan and headquartered in Columbus, Georgia. There are 14 additional boxes of ISAC-related materials in the Joseph Mahan Papers (MC 32). ISAC began as a series of Trans-Atlantic Contacts Conferences held at Westville, near Lumpkin, Georgia in 1973 and was formally incorporated as ISAC in 1983.

The organization held an annual conference, as well as occasional symposia, and published books and periodicals advocating a hyper-diffusionist view. Mahan aspired for a research center and/or museum. Name options included: the Barry Fell Center for Epigraphic Research, the Gloria Farley Museum of Pre-Columbian Writing and Symbology, among others. In 1990 an ISAC Research Center opened in the Rankin Building. In 2006 the ISAC section of the Columbus State University Archives Research Room was opened and named for Joseph Mahan. Most of the organization’s publications are held in the circulating collection of the Schwob Library. Its organizational records as well as the records of its conferences and symposia are available in the Archives. ISAC continued holding annual conferences after the death of Mahan in 1995. The 30th Anniversary Conference was celebrated in 2003. It was to be the last one held.