In American English, has the phrase "holiday season", to refer to the Christmas season, been around for a long while?
I assumed it was a recent politically correct invention to avoid mentioning the dominant religion in the United States. But ngrams has "holiday season" and "Christmas season" reasonably close to each other for as long as they've been used (going back to the 19th century). Am I mis-interpreting ngrams, is there another use of "holiday season", or has the phrase been used for a long time?