ALCO PA1 56 and mates lead Santa Fe train 3, the California Limited, west of Bernalillo New Mexico in 1947, with 13 cars at 25 MPH. Otto Conrad Perry photo from my collection.

Santa Fe's eastbound Mail Train 4 behind four Alco PA’s pauses at Wichita, Kansas before rushing onward to Kansas City.

Bringing up the rear of today's eastbound Southwest Chief (Train #4) is an Atchison, Topeka & Santa Fe passenger car, labeled #56.