Pennsylvania RR MP54 (x6)
The MP54 (https://en.wikipedia.org/wiki/PRR_MP54) electric multiple unit was introduced in 1908 and stayed in service until 1981 because no one wanted to pay for new EMUs in the United States over that whole period.
These trains could be found in service anywhere the PRR or its affiliates ran trains and had catenary: Washington DC, Baltimore, Philadelphia, $$$ ATLANTIC CITY $$$, New York City, Long Island, Harrisburg, etc. and P54 coaches found their way onto steam commuter trains in Pittsburgh.
This represents a later model built from 1926 onwards. It has a top speed of 60 mph, and absolutely terrible acceleration, much like the real thing. Each coach seats 68 passengers, as indicated by original PRR drawings. I recommend using Improved Public Transport (http://steamcommunity.com/sharedfiles/filedetails/?id=424106600&searchtext=public) to ensure the “locomotive” appears on both ends, or else you’ll get no headlight while it is travelling in reverse.
Photo licensed under CC Attribution 2.0, taken by David Wilson, retrieved from Wikipedia article linked above.
UPDATED: Now two separate files to stop dumb errors. Check out the 4-car version: