M.W. Duffy began his law practice in Cooperstown in the year 1925 and continued for 45 years until his death on June 25, 1970, at the age of 88. He was born at Camp Douglas, Wisconsin on October 31, 1881, and came to the Garske, North Dakota area as a child.
He graduated from the University of North Dakota Law School in Grand Forks, and served as Assistant Secretary of State in Bismarck before locating at Cooperstown.
He married Sarah McDonnell on November 23 1909, and they had a family of three daughters and two sons: Catherine, Beatrice, William, Miriam and Neil.
He served as state's attorney from 1939 through 1942, and from May, - 1953 through 1958. He practiced in partnership with John Sad, O. J. Thompson and A. C. Bakken at various times.
Source: Cooperstown, North Dakota 1882-1982 page 20