A Continuous Lean has an interview with Lynn Downey, an archivist and historian for Levi Strauss.
Well, [Levi's] started just as a regional thing, we had the lock on the West and other brands had their own consumer segments. I believe Lee had the South sort of sewn up, and there were some other brands, I think Lee included, that were known in New York. It's funny, you could always tell where someone was from; if they said "jeans," then they were from the west, if they were from the East they called them "dungarees," you could immediately tell where someone was from.
Update: Here's part two of the interview.