(disclaimer: these photos were "borrowed" from the web. Most of my photos came out too dark to see.)
In 1892 the train station was called Grand Central Station. The current historical building was built and opened on February 14, 1896 and today is called Union Station.
Around 30 yrs later the interior was renovated. It was then that slabs of marble were installed on floors and walls. These interior pictures make it seem fairly large, but in reality the waiting area feels small for a train station. However, it seems to be adequate for the number of people who currently use the train.
In 1920 there were five different train companies using the station with 120+ trains coming and going. It is drastically less than that now. (I'm guessing 10 trains in a 24 hr period.)
Portland Union Station is the oldest train station that has been in continous use. That's 112 years. Boy, if these walls could talk!