1. It was the first streamlined transcontinental passenger train.
2. It was the first to offer a dining car and sleeping cars.
The train was elegant and popular, providing a high level of service. However, with the advent of Amtrak in 1971, service was discontinued for the City of Portland and the other high-end trains (City of Salina, City of Los Angeles, City of San Francisco, and City of Denver.)
Here's the text of the card. (Both the Hotel White Plaza and the Titche-Goettinger store mentioned here are now registered historic landmarks.)
Room #317 - Hotel White Plaza Main + Harwood Streets, Dallas 1, Texas - Jan. 8th 1958
My darling daughter Lana J.
It was nice to see you at Xmas-New Years time and enjoyed being with you sweet. The trip to Dallas was okay with friends from Denver and Colorado Springs meeting me at the depots. Honey-child, the Titche-Goettinger Store in Dallas is right alongside of this fine hotel on Main Street side, the hotel taking up corner. Will ship you the dress when new supply comes in. More later. Lots of Love (?)