Dr. Cornelius Sedgewick was a senior attending surgeon on staff at the Lahey Clinic from 1948 until his retirement in 1984. His 42-years as a general surgeon included travel all over the world and medical experiences in several arenas.

Cornelius Sedgwick began his surgical efforts during World War II when he served as a military surgeon with the Ninth Evacuation Hospital, a MASH unit based from New York's Roosevelt Hospital. He was shipped to England and subsequently went with the Allied forces in the invasion of North Africa. From there his unit accompanied the Eighth British Army to Tunisia, Italy, southern France and Germany. Dr. Sedgwick afterwards also visited the concentration camp at Dachau, Germany after its liberation.

The greater part of Dr. Sedgwick's surgical career was spent in Boston. He was a staff general surgeon as well as a member of the board of governors and a trustee of the Lahey Clinic in Boston. He was a clinical professor of surgery at the Harvard Medical School and Chief of Surgery and a trustee of the New England Deaconess Hospital, positions he held until he retired at age 70.