The collection consists of nine series. Series One is Bobby McMillon's personal papers and correspondence. Series Two is his writings. Series Three contains Bobby McMillon's career memorabilia, including promotional materials and publications, as well as student letters and projects generated from his work as an artist-in-residence. Series Four is research materials, correspondence and writings about the Frankie Silver story, which was an important focus of McMillon's career. Series Five contains ballad and song texts Bobby McMillon collected over many years, including the fifteen "Blue Books" in which he transcribed many of these songs. Series Six has research materials on a variety of topics related to Southern Appalachian history and culture, and Series Seven contains McMillon's genealogical research on many of the region's families. Series Eight is photographs of Bobby McMillon and others. Series Nine has audio recordings, mostly audiocassettes. Some of these were digitized in 2022 with funds raised by the Bobby McMillon Legacy Project.