Like most of the houses of Steve's youth, it had three bedrooms, a bathroom, and a living room, all arranged in shotgun fashion off the main passage
Shotgun fashion? As a Brit, this was the first time I had encountered this American English term. Wikipedia explains that a shotgun house is "a narrow rectangular domestic residence... consisting of three to five rooms in a row with no hallways", and discusses the etymology of the term. I even found some plans for a shotgun house on an architectural website. And, of course, there is the lovely picture you see here.
But a bit of a discrepancy: the house described in the book has a "main passage", yet a shotgun house has "no hallways". Was St John using the phrase simply to mean that the rooms were arranged in a row? Can any American readers help? And how well known is the term Stateside? Any Brits come across it before?