I have always associated the old Wild West with the northern States of the US. California, Nevada, Arizona, Dakotas etc. In series 13.3, Blood on the Saddle, the flags decorating the Wild West Day were Confederate. Is this a blunder by the set designers or have I missed something?
shareI would argue that the "Wild West" is a somewhat amorphous region, probably bounded by Kansas as the northeast limit, south into Oklahoma and Texas, and West into Arizona, including all of New Mexico, some of Colorado and parts of California and even into Nevada. There's arguments for including Western North Dakota, Wyoming and Montana, too.
IMHO, anyway, most of the "wild west" is centered on the post-Civil War era and the viable expansion of ranching, farming and mining due to the expansion of the railroads. The Confederate flag wouldn't have fit in here.
Much of it is myth, though, not history, and its certainly possible to have something take place in the late 1860s or early 1870s and involve ex-soldiers and backstories involving the Civil War. By the 1880s, though, it seems more and more unlikely, especially as you move into west Texas, New Mexico and Arizona. By 1885 many civil war veterans would be 50 or older.
All this being said, I would expect random Europeans to easily mash up the iconography and styles of the civil war with the wild west -- old-timey revolvers, guys on horseback, etc. No different than Americans that would call the UK "England" or hear a Scotsman and say he has an English accent.