Raymond Chandler had a mixed heritage. He was born in Chicago, but spent most of his formative years (7 – 24) in Britain. He was brought up by an Irish mother, surrounded by Irish family, though they hardly slotted into neat Irish stereotypes being Protestant. Then he went to Public school where Britishness, for better or worse, was drummed into him daily.
In Europe, in 1905 and 1906, Chandler encountered plenty of Americans but later wrote that he felt he had no affinity with them. When he moved to the States in 1912 he dressed like a young aristocrat, complete with cane, sporting a public school accent that was tinged with a hint of American. So when he got off the boat, how did he feel to be back home? Did he feel American, or British, or neither? During World War I he fought for the Canadian army and then joined the RAF so it seems that Chandler took a while to decide himself.
Many years later, when he came to write his first short stories, he found that he adopted an American voice, learning the language of American English like it was foreign to him and it must be that his unique upbringing, with its medley of national influences, gave him particular insight into the power of language and it is this that made him such a great writer.