Wreck of the Old 97 lyrics question

I recently rediscovered the song “Wreck of the Old '97,” and subsequently learned about the actual wreck. It’s an interesting historical event and a great song.

The lyrics (Johnny Cash version) begin:

Well they gave him his orders at Monroe, Virginia,
Said: "Steve, you’re way behind time,
"This is not 38, this is Ol’ 97,
“Put her into Spencer on time.”

So here’s my question: What’s 38?

General discussion of the song and the wreck are welcome here too!

I thought it was just another, slower train that had no chance of making up the lost time.

38 was the Southern Railway’s fast passenger train which ran the same route and continue to N.O.

In other words, this “old 97” is slower than 38 and you need to step on the gas.

Side note–I was born in Danville VA. My grandmother was taken as a youngster to see the wreck. Hell, everyone for miles around came to see the wreck.

Damn! Just thought of another explanation.

38 was a passenger train. It could be late with no penalty.

Old 97 was a fastmail train with a government contract. You got penalized for every minute the mail was late. Maybe that was the implication.