Swanson won the first Turkey Night Grand Prixmidget-car race in 1934. At the 1939 Indianapolis 500, he was involved in the accident that killed defending champion Floyd Roberts. Thrown out of his car when Roberts hit him, Swanson lay unconscious on the track as the car overturned and caught fire. His lucky escape proved to be only a temporary reprieve, as Swanson was killed a year later while attempting to qualify for a midget car race.
In an 2006 interview, motorsports reporter Chris Economaki called him 'the best racing driver he ever saw'.