Brief Chronology
- 1909 --Born June 16 in St. Paul, MN, to Warren and Clara Dennis
- 1931 --Received BS from Harvard University (Magna cum laude)
- 1935 --Received MD from Johns Hopkins University School of Medicine
- 1935-36 --Surgical internship at University of Minnesota Hospitals, Minneapolis, MN
- 1936-37 --Fellowship in surgery at University of Minnesota Hospitals
- 1937 --Research Assistant to Dr. Owen Wangensteen
- 1938 --Fellowship in Physiology, University of Minnesota; received MS in Physiology
- 1938-39 --Instructor, Department of Physiology, University of Minnesota
- 1939 --Married Eleanor Smith
- July 1939-June 1940 --Fellow in Surgery, University of Minnesota Hospitals; received PhD in Surgery, University of Minnesota
- June-December 1940 --Fellow in Surgery and Instructor in Surgery, University of Minnesota
- 1941-44 --Assistant Professor, Department of Surgery, University of Minnesota
- September 1944-July 1947 --Associate Professor, Department of Surgery, University of Minnesota
- 1946 --Began work on heart-lung machine
- January 1947-July 1951 --Attending Surgeon and Administrative Head of Surgery, Minneapolis General Hospital
- July 1947-August 1951 --Professor, Department of Surgery, University of Minnesota
- 1951-52 --Professor, Department of Surgery, Downstate Medical Center, SUNY Health Science Center, Brooklyn, NY
- April 1951 --Performed first open-heart surgery using heart-lung machine
- September 1951-June 1959 --Director of Surgery and Surgical Specialities, Kings County Hospital, Brooklyn, NY
- 1952-February 1972 --Professor and Chairman, Department of Surgery, Downstate Medical Center
- 1955 --Performed his first successful open-heart surgery using heart-lung machine
- July 1959-February 1972 --Surgeon-in-Chief, Kings County Hospital
- October 1966-February 1972 --Surgeon-in-Chief, State University Hospital, Brooklyn, NY
- March 1972-October 1973 --Director, Division of Technological Applications, National Heart and Lung Institute, National Institutes of Health, Bethesda, MD
- October 1973-December 1974 --Special Assistant for Technology, Office of the Director, National Heart and Lung Institute, National Institutes of Health, Bethesda, MD
- December 1974-May 1988 --Professor of Surgery, SUNY at Stony Brook
- January 1975-December 1989 --Staff Surgeon, VA Medical Center, Northport, NY
- September 1975-June 1988 --Associate Chief of Staff for Research and Development, VA Medical Center, Northport, NY
- 1977 --Married Mary Mott
- March 1991-January 1996 --Director, Cancer Detection Center, University of Minnesota, Minneapolis, MN
- 2005 --Died July 11 in St. Paul, MN