The museum's sleeping car is similar to the roughly 9,000 other cars that were in operation in North American during the years prior to 1950. As most sleeping cars in North America were owned and operated by the Pullman Company (not the railroad companies) they were generally called "Pullman Cars" by the public. The term "Pullman" came to mean "1st Class Service". A passenger train with sleeping cars is a moving hotel. And like hotels today, business travelers were the primary users of sleeping cars. At one time, the Pullman Company was the world's largest hotel chain with 100,000 beds in motion on peak nights; this is larger than Marriott, the world's largest hotel chain.
The museum's sleeping car is specifically a Heavyweight Passenger Car built for the Pullman Company by The Canadian Car & Foundry Co in 1929. The Pullman Company generally assigned names to their sleeping cars based on their room layout (or Pullman Plan number). The Museum's sleeping car has a layout of 10-1-1, which means: 10 Sections, 1 Compartment, and 1 Drawing Room. These were the most common types of Pullman Accommodations prior to (about) 1940. There were 15 cars built to this plan and all the cars were named for Canadian Cities starting with the letter "S". The Museum's car is named the Saint-Hyacinthe. These cars were used in Canada, by the Canadian National Railroad.
During the heyday of the North American passenger train, many trains left late in the evening (say after 11pm) and arrived early in the morning (say 6am) allowing for a full day of business. Oftentimes the sleeping cars could be occupied a few hours before departure and be occupied until 7 or 8am upon arrival, depend on the city. Hundreds of cities had overnight sleeping car service like this, even small cities like Yakima Washington.
Below is a newspaper ad for a sleeping car from Yakima to Seattle in 1948. The car could be occupied at 9:30pm, and it would be attached to the Spokane WA to Seattle train when it arrived in Yakima just before 1:50 am. Yakima only had a population of about 38,000 then, but still had a dedicated overnight sleeper to and from Seattle for business travelers.
Prior to the 2nd World War, the Pullman Section was the most common sleeping car accommodation, and is memorialize in the movie below. The Section was the name assigned to a pair of facing couches, which at night converted to an Upper Berth and Lower Berth. The berths were sold separately, so it was common to travel in relatively close proximity to strangers (not nearly as close as that shown in the movie, however). A passenger could also purchase a Section's Upper and Lower Berth and thereby have a bit more privacy. Or, if they were rich enough, a private room could be purchased.
The following site has a good (short) history of the sleeping car, the Pullman Company, and a description of the various types of accommodations.
The Pullman Porter became synonymous with the Pullman Company. There was one Pullman Porter assigned to each Pullman operated sleeping car on the train. For African Americans - during the hey-day of the sleeping car - employment with the Pullman Company was the best job they could ever have due to endemic racism. Who can know how many potential entrepreneurs, inventors, executives, scientists, doctors, lawyers, and other Type-A personalities spent their entire working-lives as Pullman Car servants; it must have been frustrating. Imagine the quality of individuals the Pullman Company employed while paying very little. No wonder the Pullman became synonymous with "1st Class Service".