Here’s how a 1921 magazine article described the different types of ice cream:
Classes of Ice Cream
There are three distinct classes of Ice Cream: The Philadelphia, which is supposed to be made of heavy cream; the French, which is made with eggs on a soft custard foundation; and the so-called American, which is made on the foundation of a thin white sauce. All three classes are made in New York, and in every other large city, but we have never heard that any special recipe for ice cream is peculiar to New York. The less expensive form of cream, in that and every other city, are those based on a thin white sauce, sweetened sauce, sweetened, flavored, and frozen.
American Cookery (November, 1921)
A Hundred Years Ago 
That is an interesting description, sweetened sauce that is sweetened. The recipe I used was my father-in-law’s–heavy cream and a cooked egg custard base.
I am stuck on the thin white sauce.
I was hoping it did not mean flour and milk, aka ‘gravy ice cream.’ 🙂
I’m not sure I have ever tasted a real difference between French vanilla and (I’m guessing) American vanilla… I don’t think the store brands use egg, just yellow food coloring!
When I was a child, ice cream from an ice-cream van, a rare treat, came in two flavours, vanilla, and pink. A cone, or a wafer. That was it. I guess they were made from fat and sugar!
I am craving.
A white sauce? Wonder what they meant by that…. a white sauce in my mind is used for gravy.. heavy cream and eggs is what I use.
When I was growing up, I learned to make ice cream with just light cream, a little heavy cream, sugar, and vanilla or other flavor, no eggs. My mother said using eggs made it “frozen custard” and not ice cream. Not sure what the white sauce was, it says thin, but I wonder if it was thickened with cornstarch or something.
I remember there being a clear distinction between ice cream and ice milk in the 1950’s. Perhaps that was a remnant of the thoughts in the 20’s.
Wouldn’t it be fun to have a taste test? Maybe not. I’m addicted to a local brand, and I’m not likely to switch my preference.
Texas’s favorite brand, Bluebell, produces three kinds of vanilla: ‘homemade’ vanilla, French vanilla, and natural vanilla bean. It’s interesting that the three have distinctive tastes. The homemade does taste like freshly churned, and it’s their best seller.
I think it would mean flavoured milk vs custard base… which is what I use for my ice creams.