It was probably around 1969 as I worked at a snack and icr cream parlor, a huge one, that Summer. I am sure the manager told me butter pecan was the most popular but I think I also read it somewhere too.
I just looked it up and the site I used said vanilla number one, chocolate number two and butter pecan third. At least it is still up there with the top ones.
We used to eat butter pecan and black walnut—both so good.