On June 2, 1946, the Union Pacific and Wabash railroads began operating the City of St. Louis from St. Louis to Cheyenne. The train went over Wabash rails from St. Louis to Kansas City and UP rails from Kansas City west. At Cheyenne, the train was broken up and parts joined the City of Los Angeles and parts the City of San Francisco. But starting in 1951, the train operated as a unit from St. Louis to Los Angeles.
Dated August, 1958, this brochure indicates that the City of St. Louis has both a dome-coach and a dome-lounge. Click image to download a 1.7-MB PDF of this four-page (eight-panel) brochure.
The train became a domeliner in 1956 when the Union Pacific combined the all-coach Challenger with the all-Pullman City of Los Angeles, at least in the off-season. Since both trains had a dome-lounge, Union Pacific transferred the Challenger‘s dome-lounges to the City of St. Louis for the use of sleeping-car passengers. Soon after this, Union Pacific modified its dome-lounges for mid-train operation by adding a diaphragm and blocking the rear windows.
Here is the City of St. Louis before the dome-coach was added and before the dome-lounge was modified for mid-train operation. Someone has mixed-up the tail sign: instead of reading “Domeliner City of St. Louis” it says “of St. City Domeliner Louis.” Click image for a larger view.
In 1958, the Union Pacific ordered five more dome-coaches, and the Wabash ordered one painted in Union Pacific colors, so the City of St. Louis could have two domes. These cars, the last classic dome cars ever built, were similar to UP’s other dome-coaches but were built by Pullman rather than American Car & Foundry.
Another early photo of the domeliner City of St. Louis–note that the dome-lounge is coupled to a heavyweight car. Here, the tail sign reads “City of St. Louis Domeliner,” which isn’t quite as mixed-up as the previous one. Click image for a larger view.