The tradition that continues to this day began in 1946 when the three Webb brothers joined in a race to see who had the swiftest horse.
According to news reports at the time, "practically the whole town went to the Adelaide River by a special train." That town was Darwin, Northern Territory, Australia.
Picnic Day events stretch back in time to the 1800s when Northern Territory rail workers took some time off to eat and hang out near the Adelaide River.