But not that old. These ships are in the destroyer series.
Long time ago in the Last World War there was a cruiser series, a destroyer series, abs a destroyer escort series.
Late 40s they added a Destroyer leader (DL) series, in the 50s a Missile Cruiser series, and the 60s saw a missile destroyer series, and a missile destroyer escort series.
In the 70s the DL series was eliminated, the lowest numbered shipd being renumbered into the Missile Destroyer DDG series, the others going into the top of Missile Cruiser CG series with their original numbers.
By this tome the CG series is up top CG-45, the DDG series is up to DDG-46, the original destroyer seres is up to DD-997, the nissile destroyer escort series is not the missile frigate series FFG-61, the destroyer escort/frigate series is at FF-1097.
Now the Ticoderogras DDG-47 up are reclassified into the CG series, and because the first 4 already had numbers assigned, the DDG series goes on from DDG-51.
But because the Zummwaldts aren't really missile destroyers (ie area AAW defence ships) they follow from the destroyer USS-997 Hayler
