This song appears on page 355 in Sandburg's "American Songbag" as "Bolsum Brown":

BOLSUM BROWN
Who he was, this Bolsum Brown, and who she was, the Sister Mary referred to, we do not know. And nobody cares. But the song passes the time among the people who work for a living.

There's a red light on the track for Bolsum Brown
For Bolsum Brown, for Bolsum Brown.
There's a red light on the track,
and it'll be there when he comes back,
There's a red light on the track for Bolsum Brown.

Hop along, Sister Mary, hop along,
Hop along, hop along.
There's a red light on the track,
And it'll be there when he comes back.
There's a red light on the track for Bolsum Brown.