When as Kanas Kansas State interupted, or Clemson South Carolina, or Oklahoma Oklahoma State. WW2?They are, but both series have been interrupted. That's what makes Farmageddon the longest consecutively played series in the country.
There have been series that date back farther. There are series that have been played more times in a row. All of those series have taken a year off at least for one reason or another. Since ISU and KSU first met in 2017, they've never missed a year. No other uninterrupted series has started earlier.