The Henry S. Leonard papers contain materials from Leonard's academic career beginning as a student, course materials including syllabi from Leonard's time teaching at Duke University and Michigan State University, notes, drafts of Leonard's publications, and finished articles and publications. There is also material related to societies Leonard belonged to as well as a small amount of correspondence. A book honoring Leonard and his work, as well as two Process Studies journals from 2013 about Alfred Whitehead which also contain mentions of Leonard round out the collection.