According to Wikipedia, the Chicago, Aurora and Elgin “abruptly ended passenger service” at noon on July 3, 1957, leaving commuters stranded in Chicago. It ran its last freight train two years later, leaving the South Shore as Sisk’s only client mentioned on the blotters.
Art by Earl Moran.
Art by Gil Elvgren. I don’t know how much longer Sisk continued to distribute pin-up blotters, but increased numbers of women in the work force in the 1960s made them commercially less appealing.
George Sisk wasn’t the only railroad marketer who used pin-ups on blotters. Here are two from the Rahway Valley Railroad of New Jersey. They are undated but, like the Sisk blotters, would be from the 1940s or 1950s.
The Rahway Valley Railroad was a short-line that bridged the gaps between the Lehigh Valley, Lackawanna, and Central of New Jersey. Though it had been highly profitable, when all three of those railroads were taken over by Conrail in 1976, the reason for its existence faded and it ceased all operations in 1992.