"Wabash Cannonball" is based on a song that was published in 1882 under the name "The Great Rock Island Route" (written and composed by J.A. Roff).

Some people think the "Wabash Cannonball" is a mythical train. It seems to have actually been a train running for the Wabash Railroad (which was formed in 1837)*.

Notes

*According to "Atlas of North American Railroads" by Bill Yenne.

The Wabash was built in 1880 and was fast for its day (according to "Roy Acuff, the Smoky Mountain Boy" by Elizabeth Schlappi). The Cannonball ran between Detroit and St. Louis during its last years in operation (according to Railroad History, Issues 132-134 by Harvard University. Graduate School of Business Administration, Railway & Locomotive Historical Society). Later, many trains were called the Wabash Cannonball because of the popularity of the song.

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Here's the song that Wabash Cannonball was based on. The lyrics and music were written by J. A. Roff (1882):

The Great Rock Island Route

From a rocky bound Atlantic, to a mild Pacific shore,
From a fair and sunny southland to an ice-bound Labrador,
There's a name of magic import and 'tis known the world throughout,
'Tis a mighty corporation, called the great Rock Island Route.

(Chorus)
Now listen to the jingle, and the rumble, and the roar,
As she dashes thro' the woodland, and speeds along the shore,
See the mighty rushing engine, hear her merry bell ring out,
As they speed along in safety, on the "Great Rock Island Route."

All great cities of importance can be found along its way,
There's Chicago and Peoria and Rock Island so they say,
With Davenport, and westward still is Council Bluffs far out.
As a western termination of this Great Rock Island Route.

(Chorus)

To the great southwest another, and a mighty line they run,
Reaching far famed Kansas City, Leavenworth and Atchison,
Rich in beauty, power, and grandeur, and they owe it all no doubt,
To the fact that they are stations, on the Great Rock Island Route.

(Chorus)

There's the "Northern Route," a daisy as you all can plainly see
To St. Paul, and Minneapolis, 'tis the famous "Albert Lea,"
To the lakes of Minnesota, and all points there 'round about
Reached directly by no other, than the "Great Rock Island Route."

(Chorus)

Now let music soft and tender, in its mystic power reveal,
Praises to the "Great Rock Island," that the heart can only feel:
And to swell the mighty chorus--comes the glad re-echoing shout,
That for safety, time and comfort, take the "Great Rock Island Route."

(Chorus)

The original score for this song is online.

Wabash Cannonball - American Children's Songs - The USA - Mama Lisa's World: Children's Songs and Rhymes from Around the World  - Comment After Song Image