Get Engaged at Christmas! reads this 1934 advertisement for R.M. Hurlbert, a Worthington jeweler.
My immediate and admittedly very cynical thought was "Because the holidays weren’t stressful enough!" but it is sort of a sweet idea to pop the question in front of the people most important to you. Provided you have discussed it already with your potential spouse, at any rate.
I really like the designs for the rings in the advertisement. They’re a lot more complex than what I’d want in an engagement ring (’cause I’d be wearing that every day, obviously), but they are awfully pretty in that art deco style.