In the novel, 'The Great Gatsby' a character is asked "What part of the middle west?" And his answer is "San Francisco" I looked up what is the mid-west of the US today, here is a picture. If you don't want to click it, know that San Francisco is no where near the shaded area, it's on the other side of the country.
So I'm wondering if, in the past, the mid-west was not the same as it is today. Simple question really, but google hasn't turned anything up, except city plans.
Without knowing the full context of this expression, we can take this to be either a joke or an expression of the provincialism of an Eastern who does not understand geography beyond the Atlantic Seaboard. San Francisco has been consistently regarded as part of the "West" or better the "Far West."
Although the frontier - what the East regarded as the west - extended gradually over time from the place "just beyond the settlement," by the mid nineteenth century the terms and the educated perception was locked in. The old west of the Mississippi and Ohio drainages had become known as the Midwest, and the land from somewhere just east of the Rockies to the Pacific Coast became known as the West. Your character in "The Great Gatsby" should have known this, so he was either expressing his ignorance or trying to be funny - only context can determine which.
I can't answer the question but I can explain why Gatsby said what he said. Jay Gatsby as he exists is an alter-ego who possesses immense wealth and renown as created by the son of poor-farmers. He wasn't schooled well and his only way out was to enlist in WW1. Fitzgerald drops hints in the novel that Gatsby isn't quite what we think and this is one of them to begin our confusion as to Gatsby's past.
