Sorry I'll try to say that a bit more clearly. The City of New Orleans was the first train to lose it's full dining car, unless you count the Cardinal.
Here's the current City of New Orleans menu which is all pre-prepared food, but served in the traditional dining car style, with table service. -
https://www.amtrak.com/content/dam/...s-Southbound-Tran-59-Dining-Car-Menu-1017.pdf
Prior to that, the City of New Orleans operated a traditional full dining car service, in a physical CCC car (the way Texas Eagle does now.)
At the introduction of the CCC cars, the Texas Eagle and the City of New Orleans both had a specific CCC car menu and service that didn't last long... here's a link to a review that includes the full written menu of the original CCC cars -
http://www.trainweb.org/chris/nod.html
And before that the City of New Orleans operated a full dining car.