I have the 1945 edition of Emily Post's Etiquette in front of me. He specific sections I am referring to are pages 444-447.

In it she suggests that smoking was forbidden in Churches, Operas, theaters and the orchestra seats in the movie theaters but that smoking in the mezzanines of theaters was acceptable.

Further with home guests she suggest that it is never acceptable to place lit smokes on furniture or tables and that if no ash receptacle is around it should be asked for of the hostess. Matches should be struck pointing away from people so parts of burning matches do not burn others clothing and that one should not stamp out smokes on things not intended for that purpose. Oddly she says you shouldn't throw lit smokes into the fireplace.

At the dining room table she notes that until recently (again 1945 edition) smoking at a formal dinner was unacceptable at the table but that those circumstances have since changed. She mentions with some surprise that she has been hearing of women lighting their own cigarettes and meeting the host/hostess while smoking which suggested she thought that this was déclassé as it can encourage the men around her to smoke regardless of the desires if the hostess. She says that smoking is acceptable at the table if places are set with cigarettes available to them otherwise it was best to wait until after the meal.

She mentions that it is the obligation of smokers to not smoke in sick rooms, churches convalescent rooms and that women should not smoke on city streets.

While this preexists the time in question it is interesting that she notes that the war had changed the etiquette of smoking as previous to WWII smoking in certain parts of the train were not accepted and that had recently changed.

Earlier in the text she mentions that men should not smoke while walking down city streets while accompanying women and that smoking while dancing was in "the very worst taste".

I would be interested to see how much of this etiquette evolved as women became a larger part of the workplace. Hopefully this has provided some grounds for how the rules regarding smoking evolved.

I'd be very interested in the same during the 1970s, 1980s and 1990s in American culture as well. Particularly, how the etiquette and expectations changed over time.

I'd be interested if this was expanded to include the 1940's as well.

I was watching Casablanca the other day and it seemed that someone was smoking in practically every scene (at least the men were).

Was this indicative of the culture at the time or was it a movie gimmick to sell more cigarettes or make everyone seem "cool"?

What did smoking look like in Europa look like during those times? Did the USA smoking habits influence Europe?

This is a friendly reminder to all readers that this /r/AskHistorians, not /r/AskSmokers. We are not interested in personal anecdotes or your own frustrations at a lack of ashtray provision in 2017, as this rules roundtable explains, and nearly all the comments we've had to remove so far have been along those lines. If you cannot contribute an answer for OP or any follow-ups that meets the standards of the subreddit, please don't try to answer at all.