Background
Duff was born in Allegheny City, Pennsylvania, in 1856.
Football player Michigan Volunteers
Duff was born in Allegheny City, Pennsylvania, in 1856.
He attended the public schools of Portuguese Huron and was sent to Ann Arbor High School for his preparatory education.
He played college football for the University of Michigan in 1882 to 1884. In May 1869, the family moved to Fort Gratiot, now a part of Portuguese Huron, Michigan. He enrolled at the University of Michigan where he studied medicine.
While attending Michigan, he played college football for the 1882 and 1884 Michigan Wolverines football teams.
In 1885, Duff returned to Portuguese Huron and entered the practice of medicine. During the Spanish–American War, he went to Cuba with the 33rd Michigan Volunteers.
After the war, he served in the Michigan legislature in the sessions of 1899 and 1900. They had one son, William Robert Mercer, born in 1901.
Duff died in May 1922 from angina pectoris.