If you are interested, I found a great website. The LA public library has a searchable database of menus from Local ( and not so local) restaurants. Banquet menus from 1909, Seafood restaurant menus from the '30's. the selections (prices aside) are so much more varied than I'd assumed. Anyway, check it out. It's a lot of fun, at least I thought so.
Also, the regional history databases can be found at