Southern stayed out of Amtrak for several years. One of the provisions of the initial Amtrak act was that a railroad that stayed out had to continue all passengers for some minimum period. I think it was 5 years, but it may have been less. By Amtrak time Southern was down to four trains, three trains out of DC, one, the Southern Crescent, going to New Orleans, but only 3 days per week south of Atlanta, one ending in Atlanta, and one, the remnant of the Birmingham Special which had been turned over to N&W at Lynchburg and ending at Bristol VA/TN where before being cut back it was turned back over to Southern for the rest of its trek. The Crescent was maintained as a high quality run, normally having 4 E-units on the front, the Atlanta train which operated as a day train was also well kept, but normally had a string of piggyback cars added at their Alexandria yard, which was south of Alexandria passenger station, not at Potomac Yard, and the third a single coach which was hauled by a single engine out of DC to their Alexandria yard where it became part of a piggyback train for the rest of the way. The coach was not even pulled off at Lynchburg so as to save switching. (I rode this one once.) The other train ran Salisbury NC to Asheville NC as a connection to the Atlanta day train. Westbound it was after dark, but eastbound it was a beautiful scenic ride. After they were allowed to start cut offs again, the Asheville train disappeared along with Lynchburg coach in a freight train and the day train cut back to Charlotte NC.
Although 100% Southern owned, the Central of Georgia had maintained a separate corporate identity and did join Amtrak. There were squawks about that but they were able to make it stick. This allowed them to discontinue their Atlanta - Savannah train and their portion of the City of Miami.