I was intrigued by the song City of New Orleans about the train of the same name. I did some searching and found that there was at least a handful of trains named "city of X" in the US throughout the 20th century.
Where did this practice start? I assume they were named after a major city on their route?
Did the name refer to any train that ran that route, or an individual specific train?
That's one of my all-time favorite songs!
Only about a dozen trains, from 4 or 5 railroads, had "City of" names. I'm still trying to figure out which was the first, but it probably was in the early 20th century. Union Pacific, I think, ran the most, with a "City of San Francisco," "City of Los Angeles," "City of Denver," "City of Portland," "City of St. Louis," and a few others. In the waning days of passenger trains, just prior to Amtrak, several of the western trains were combined, an operation railfans jokingly called the "City of Everywhere."
From the earliest days of American railroading, trains were known by number. As competition intensified on long-distance routes, railroads began marketing their trains with luxurious equipment and service, and new names for the line's premier trains, such as the "20th Century Limited," the "Southern Belle," or the "Dixie Flyer." Named trains nearly always referred to a single train operation, usually both directions. Train numbers would differ by direction, so the westbound City of LA was Train 103, while the eastbound was Train 104. Other trains running the same route would have other names (the Illinois Central's Panama Limited also ran Chicago–New Orleans), or merely numbers for slow, local runs. Exceptions would be a few high-intensity "services" like the Pennsylvania Rail Road's "Clocker" service running hourly between New York and Washington. A modern example is Amtrak's "Hiawatha Service" several times daily between Chicago and Milwaukee.