Prior to this year, the entire country. Today, thanks to SCOTUS shenanigans, it likely only applies to the states involved in the lawsuit, LA. But who knows, hard to keep up with the game of calvinball the SCOTUS is playing.
Now we have the weird situation where the constitution is more patchwork because you have to get rulings in all the Circuits or wait for one case to make it all the way to the Supreme Court.
Regardless of what you think about nationwide injunctions, your original assertion that “prior to this year,” a decision by a federal appellate court would apply the entire country is categorically false.