"On the Atchison, Topeka and the Santa Fe" is a popular song written by Harry Warren with lyrics by Johnny Mercer. The song was published in 1944, spanned the hit chart in mid-1945, and won the 1946 Academy Award for Best Original Song, the first win for Mercer.
The song refers to the eponymous fallen flag railroad, and was featured in the 1946 film, The Harvey Girls, where it was sung by Judy Garland, with support from Ben Carter, Marjorie Main, Virginia O'Brien, Ray Bolger, and the MGM Chorus.
At one point in mid-1945 versions by Mercer, Bing Crosby, and the Tommy Dorsey Orchestra were on the hit chart simultaneously. In late September the Crosby version, first to make the chart, was joined by one by Judy Garland and the Merry Macs.
Mercer said the lyrics came to him when he was sitting on a Union Pacific train, and saw another train labeled "Atchison, Topeka and Santa Fe'" and he was struck by the rhythm of the words. Despite mentions in the lyrics of the song, the AT&SF never directly reached Laramie, Wyoming (Milwaukee Road or Great Northern Railroad) or Philadelphia, Pennsylvania (Reading Company, Pennsylvania Railroad or Baltimore & Ohio).