Why San Franciscans used to sound like New Yorkers

San Francisco English has been described as dialectologically distinct from the rest of California, as indicated in the earliest studies (DeCamp 1953) up through The Atlas of North American English (Labov, Ash, and Boberg 2006). Just as Carmichael (2024 [this volume]) describes for New Orleans, the evidence suggests that vowel changes in San Francisco English “defied straightforward classification into neighboring dialect areas.” However, the distinction seems to have faded among those speakers born after the 1970s (Hall-Lew 2013; HallLew, Cardoso, and Davies 2021). We can therefore ask: What was the nature of this distinction? What did the dialect sound like? Where did it come from? Who spoke it? And why did it change?