It is in the 1950's and the U.S. economy is booming.  Railroads are working hard to move freight across the country. Passengers are continuing to travel by train as in the World War II period.  Due to the heavy rail traffic, the railroads have had to supplement new diesel power with steam locomotives. Coal is cheap and so is oil, thus both types of energy are fueling steam. 

The weather in the central part of the country has made rail traffic congested. The Mississippi and Missouri Rivers are over flood stage.  The Mississippi can only be crossed at St. Louis and, thus, all east west movement is through the St. Louis Gateway, whether from Chicago or south to New Orleans. 

The Missouri River at Kansas City is the only crossing in Missouri and so northern and southern movements west of St. Louis must route through Kansas City.