Amtrak Northeast Regional train 171 is roughly 460 miles into its nearly 500-mile journey from Boston, Massachusetts, to Manassas, Virginia, as it passes through Washington DC. AMTK P42DC 190 was added just a couple of miles back, at Washington Union Station, replacing the ACS-64 electric locomotive that pulled the train on most of this trip. The iconic dome of the United States Capitol looms in the background. (Washington DC – April 15, 2022)