Casey Jones, he died at the throttle, Casey Jones, with the whistle in his hand

Ah, the importance of worshipful friends or family in building a legend.

John Luther Jones from Cayce (pronounced Cay-see), Kentucky, famous to us through song as a brave engineer who romantically died trying to make up time. In truth, he crashed his locomotive at high speed into a freight train that was attempting to get out of the way on a siding. According to reports he failed to heed warning signals that were out. The accident took place early in the morning of April 30, 1900. Jones was the only fatality.

Jones was known for his affability and his skill in blowing a train whistle. His engine wiper, Wallace Saunders, reportedly idolized the engineer. Saunders wrote the original song.

All you might want to know can be found in this 1928 article.