An announcement in the August 6, 1904 issue of The New York Times indicated that the Metropolitan Association of the Amateur Athletic Union would hold a "special five-mile race" at Celtic Park on August 13, 1904 with the eight top finishers receiving a paid trip to compete in the marathon at the Olympic Games in St. Louis on August 30, 1904.[2] Cohn was named as one of 19 "probable competitors" in the event.[2]
In the 1908 Olympic Games, 3 miles team race, he finished in twelfth place. As the last American to finish, he was not awarded silver medal. (Only three fastest of each team were awarded a medal).