When I was very young (preschool young) back in Chicago we lived half a block away from the GTW railroad tracks. There used to be a regular passenger train (My Dad called it the "Canadian Express") that was pulled by a big steam locomotive - my Dad and I often would walk over to the RR crossing to watch it go by.
I remember my terrible disappointment when one evening the train came by pulled by one of the "new" diesel locomotives. This was probably about 1960, give or take a year or two. I imagine I witnessed one of the very last steam locomotives in regular service - the end of an era.