He had a brother, Frederick Blackman Mumford (1868-1946). He worked at the University of Illinois at Urbana–Champaign and was the department head for animal husbandry from 1901 to 1922. He was dean of the UIUC College of Agriculture and the director of the Agricultural Experiment Station and the cooperative extension service from 1922 till his death.
He died in 1938.
On June 27, 1946 the board of trustees of the University of Illinois approved a resolution to rename the agricultural building Mumford Hall. The renamimg took place on April 17, 1947.