Transportation, distribution, mass marketing (Farrah may have helped a little) got the name out and soon Dr. Pepper became available everywhere. Then in the 80's came the high fructose corn syrup version and it really wasn't quite the same. (In the 2000's the diet version made it tolerable to me again.)
Word spread of the original still being bottled at the original plant in Dublin, Texas with real Imperial Cane (Texas brand) sugar. Dublin became one those places to go to bring back some of the original as if some "G" rated version of Smokey and the Bandit. Coming on-line, the internet made this sugary sweet Texas tonic available everywhere once more; some local grocery stores even had it on their shelves (rumor was you could sometimes find it at Walmart).
Enter Dr. Pepper/Snapple, who decides this little bottling plant in Dublin, Texas was working outside of their territory (making more than their share?). Long story short, Dublin Dr. Pepper has been bought out, 14 plant employees laid off, gift shop cleared and all evidence of Dublin Dr. Pepper has been removed. The sugar formula will be made at a big plant elsewhere.
Turn off the light to the little town of Dublin and the end of an era.