I don't remember where I read this anecdote, probably here, that American aircraft had to at least make it from one end of Texas to the other.
It's a big country. I doubt there was a requirement written as such but thought along those lines must have been there. That might explain why American fighters were larger than their European counterparts.
Los Angeles is closer to El Paso than Texarkana. Texarkana is closer to Charlotte, NC than it is to El Paso.