Abstract Ralph Waters, the founder of the anesthesiology department and residency program at the University of Wisconsin–Madison, and John Lundy, the chair at the Mayo Clinic beginning in 1924, collaborated to expand regional anesthetic techniques and knowledge not only at their institutions, but also at institutions around the country through correspondence, meetings, and hosting of other anesthesiologists. The Ralph Waters Collection at the University of Wisconsin Archives was searched for information on Waters' and Lundy's involvement in regional anesthesia. This included publications by Waters and other anesthesiology department faculty, as well as personal correspondence with other leaders in anesthesia at that time. Correspondence between Waters and Lundy from this collection was reviewed in detail. This article underscores the importance of exchange of ideas by physicians through didactics, organizations, and research through the story of Ralph Waters and John Lundy's mutual exchange of ideas and even friendship beginning in the 1920s.