Austin is the older race, and for a while it was the only American GP.
They do the same for other countries too; Monza has always been the Italian GP, but had we raced at Imola this year, that would've been the Emilia Romagna GP.
2020 also showed they'd do something with back-to-back races at the same track; Austria, Great Britain, and Bahrain all had one "definitive" GP each, but the followup race was called something different.
Driving a Trabant through the desert. Occasionally shooting rabid bunnies.