My favorite Guy Clark song, given that I'm a train buff, is "Texas 1947", which you can hear in the clip above, along with "Let Him Roll", also from his first album, Old No. 1. "Texas 1947" is autobiographical, telling of his going at the age of six to "the depot" in his hometown, Monahans, Texas, to see something new.
That "something" proved to be a streamlined passenger train, no doubt the Texas Special of the Texas & Pacific Railroad (photo above), pulled by a then novel diesel locomotive ("Big and red and silver, she don't make no smoke"). Although he was five years my senior, Clark and I shared seeing what railfans call the "transition years", when steam gave way to diesel.