A few comments about Southern. When A-day arrived, they were still running a train to Asheville (a connection at Salisbury with a through train to Atlanta), and the "Birmingham Special" to Birmingham via the N&W. They ended up having to run the Southern Crescent, the Asheville train, and a stub WAS - Lynchburg train for a few years, but quickly got rid of the stub and the Asheville train.
Rock Island was still running dining cars on the trains to Peoria and Rock Island in the early 1970s, along with Ben Butterworth's ex-DRGW dome-obs "Big Ben". The diners went in 1975 -- I remember because, in the summer of 1976, I worked for the Rock and we were still drinking the inventory of dining-car coffee. It was a special blend for the RI and it was delicious. Although I worked for the Rock, for a variety of reasons I never managed to ride either passenger train before they were discontinued in the late 1970s.
The RDG was still running trains to Pottsville (about 100 miles from PHL), Allentown, and of course Newark in the late 1970s. The "Crusader/Wall Street", which ran with ex-B&M RDCs, lasted until a big New Jersey cutback in 1982 that also saw the elimination of service to Phillipsburg over the CNJ (the "Queen of the Valley" train carried the ex-Blue Comet open-platform obs) and to Atlantic City, Ocean City, and Cape May from Lindenwold. The other RDG trains lasted until the Center City tunnel entered service in 1983. The tunnel was not designed for the operation of diesel equipment, so service to Pottsville and Allentown was ended.
Interestingly, the extension to Allentown from Bethlehem was funded by the local transit authority in the Allentown/Bethlehem area, and used the former Lehigh Valley (still used as a bypass around Allentown Yard by NS). The train stopped at the RDG station in Bethlehem, ran through the connecting track onto the LV, and terminated at a gravel platform within sight of the vandalized wreckage of the former Allentown passenger station.