Green’s Dictionary of Slang

Casey Jones n.

[the legendary locomotive engineer John Luther Jones (1864–1900); his nickname came from the town of Cayce, pron. Casey, Kentucky; his fame from his death, attempting to avoid the crash that killed him, which event was later immortalized in a poem by Wallace Stevens, an engine wiper]
(US)

1. [1930s+] (also Casy Jones) a train-driver, a locomotive engineer.

2. [1940s+] a railway train.