The Mayo Clinic came to be regarded as one of the foremost medical treatment and research institutions in the world.

A close and enduring relationship between the Mayo Clinic and the University of Minnesota Medical School developed.

[1] During World War I, Mayo and his brother served as chief surgical consultants for the U.S. Army.

[1] From 1919 to 1936, when he retired, he was a member of the Senate of the University of Minnesota and professor of surgery in the UMN medical school.

Charles Mayo's wife was Edith Graham, of Rochester, MN, whom he married in 1893.

He belonged to the Episcopal church, and was a Freemason and member of Rochester Lodge #21 of the Grand Lodge of Minnesota, AF&AM, a Knight Templar, Scottish Rite Mason and Shriner, a Kiwanis, and was active in numerous other professional, civic and social clubs.