I just found this great resource for people looking for vintage menu guidance (see the link down below). The Los Angeles Public Library has a database of old menus from both LA and the rest of the country that shows what people were eating. A lot of them are menus from formal dinners, and most of them are scanned and available on their website. You can search by decade by typing, for example, 193* or 195* in the date field, that will get you menus from all the years of that decade.
http://www.lapl.org/resources/en/menu_collection.html