The actual 30-mile rail run (each way) is bucolic, with little scenes that look like they were contrived for a model railroad exhibit. There are some nice little wildlife areas, and some interesting rail yards, even a little coal and quarrying. There was training site for bus and truck drivers (these are "real jobs").
I had never ridden on a commercial (non-Metro) train south of Union Station. The tunnel actually starts just south of the Library of Congress and Capitol South Metro, and runs underneath and slightly around the Capitol to get to Union Station. Congress has it's own little railroad and subway, which we can talk about later.
There is only one afternoon train inbound on Manassas (none on Fredericksburg). Amtrak itself has very limited service on these lines. Oddly, outbound, the train stayed on the Left, British style.
(There was a video here. Amazon link for purchase of music is here. Hope the entire video is available there soon there, as on a DVD perhaps, with other material; I'll advise if this happens..)
And before the exercise, I tried lunch at the Red Robin across the street, when a slip-up in customer service almost made me too late.