I don't see it explicitly stated, but since the times are exactly the same for the James Whitcomb Riley and the Mountaineer between Chicago and "Tri-State"/Ashland, it looks like these ran as a single train from Ashland west, joining/splitting there?
I'm piecing together the following from Wikipedia and other sources, and some of the information is hazy or contradictory... please confirm or correct the below if you know better:
pre-A-Day:
1923: B&O inaugurates the Capitol Limited, NYP-BAL-WAS-Cumberland-PGH-CHI
1925: B&O inaugurates the National Limited, NYP-BAL-WAS-Cumberland-CIN-STL
1926: PRR stops allowing B&O to use NYP, and B&O relocates their northern terminus to Jersey City
1932: C&O inaugurates the George Washington, WAS-Charlottesville-Clifton Forge-Ashland-CIN; a second section operates NPN-Richmond-CVS, joining the main section there -- the main section is basically half of today's Cardinal
1941: NYC inaugurates the James Whitcomb Riley, CIN-IND-CHI -- this is basically the other half of today's Cardinal
1946: N&W inaugurates the Powhatan Arrow and Pocohontas, Norfolk-Lynchburg-Roanoke-Bluefield-Kenova(Ashland)-CIN -- this was basically the Mountaineer, and also the basis for the Hilltopper
1958: B&O abandons service north of BAL; CL and NL now run BAL-CHI and BAL-STL respectively
1965: C&O takes control of B&O, and attaches the NL to the GW from WAS to CIN, effectively extending the GW to STL
1966: C&O/B&O abandons BAL; CL now originates in WAS, as does the GW/NL combined train
1969: N&W discontinues the by-now decrepit Powhatan Arrow but upgrades the Pocahontas.
The Capitol Limited (now WAS-Cumberland-PGH-CHI), George Washington (now WAS-CVS-CLF-Ashland-CIN-STL, with NPN section), James Whitcomb Riley (CIN-IND-CHI), and Pocahontas (Norfolk-LYH-ROA-Bluefield-Ashland-CIN) continue to A-Day.
A-Day:
Amtrak drops the Capitol Limited entirely.
Amtrak drops the Pocahontas entirely.
Amtrak drops the CIN-STL service formerly provided by the GW/NL.
Amtrak briefly continues to operate both the GW and JWR as separate trains; then in November merged the two into a single train and extended it all the way up the NEC to BOS, running a BOS-NYP-PHL-WAS-CVS-CLF-AKY-CIN-IND-CHI route, confusingly named GW eastbound and JWR westbound.
post-A-Day:
1972: Amtrak cuts the GW/JWR back to WAS.
1974: Amtrak drops the GW name, and uses JWR for both eastbound and westbound.
197x: Amtrak extends the JWR to NYP, essentially today's Cardinal's route. But there were various route changes in the midwest through the 1970s.
1975: Amtrak creates the Mountaineer, Norfolk-Lynchburg-Roanoke-Bluefield-Ashland, joining the JWR at Ashland and continuing to CHI -- more or less re-creating the Pocahontas. (so, from 1975-76, there were basically three sections to the JWR? the main section, the NPN section joining at CVS, and the Mountaineer section joining at Ashland???)
1976: Amtrak drops the NPN-Richmond-CVS section of the JWR. Amtrak replaces this with the Colonial, NPN-Richmond-WAS-NYP.
1977: Amtrak drops the Mountaineer, but creates the Hilltopper to more-or-less cover the same route (this time from the NEC instead of from Norfolk): BOS-NYP-PHL-WAS-Richmond-LYH-ROA-Bluefield-Ashland, with a six-hour connection to the JWR/Cardinal at Ashland. (did the cars join? or did passengers have to change trains? I haven't found that out)
1979: Amtrak drops the Hilltopper. For about eight months, Lynchburg had two "Amtrak" trains (as the Crescent became Amtrak in February and the Hilltopper was dropped in September). The Hilltopper had been trains 66/67, running overnight from BOS-WAS, so my guess is they actually just trunctated it at WAS and re-named it the Night Owl, then in 1997 re-named again to the Twilight Shoreliner. But I don't know.
1981: Amtrak re-creates the Capitol Limited, following the original B&O route from WAS-PGH but not from PGH-CHI.
1992: Amtrak re-names the Colonial the Old Dominion.
1997: Amtrak creates another Colonial running the same route.
later: Amtrak drops all Regional train names.
2009: Amtrak extends a Regional through CVS to LYH (with plans to continue to ROA). There's really no perfect historical analog to a BOS-NYP-PHL-WAS-CVS-LYH-ROA train... but Hilltopper might be the closest.
Sources included... American Rails (
George Washington,
National Limited), a book abstract on the
Capitol Limited and National Limited,
Streamliners (at
Google Books, pages 38-47), and various Wikipedia pages (the Cardinal, the Virginia Services, etc).
edit: Oh, I just found
a railroad.net thread which also discusses the Shenandoah and gives more info on the Hilltopper, Mountaineer, etc. Maybe I'll try to revise the above. What exciting times the mid-'70s must have been for anyone living along these routes... never knowing when their train might stop this year or what it might be called....