A fine professional lightweight boxer in the early years of the 20th century, he retired to Cleveland and opened a gymnasium on the city’s West Side which was to produce some of the nation’s best fighters under his tutelage. His first renowned pupil was Johnny Kilbane who won the world featherweight title in 1912 and retained his championship for 11 years. Two other Dunn-trained boxers, bantamweight Carl Tremaine and middleweight Bryan Downey, fought the reigning world champions and are members of the Greater Cleveland Sports Hall of Fame.