Having won sprint events at the 1903 American and Canadian championships, Hahn was among the favourites at the 1904 Olympic Games in St. Louis, which was poorly attended by European athletes.
In the first event at those Games, the 60 m, Hahn benefited from his quick start and won, making him a favourite for the remaining events he was entered in, the 100 m and 200 m. His run in the 200 m final delivered him the gold and a good time, although the latter was flattered, because the race was run on a straight course. In his third event, he again outclassed the field, winning all sprint events.
In 1906, the "Milwaukee Meteor" repeated his Olympic victory in Athens, a feat not equalled until 1988, when Carl Lewis won the 100 m twice in a row.
After his running career, Archie Hahn became a coach and wrote the classic book How to sprint.