"Jean B." writes, from a "Boston-area" location:

It's great to have all of these first-hand memories from you.
I am 57, and all I can say that I personally remember is
root beer made from the syrup and soda water at the town drug
store, which was conveniently situated between school and
home. They had a much mellower flavor than what I find bottled.

Gee, after all this, I think I'll forget dinner and have a...
root beer float.... :-) I have the root beer but may need
to run out and get some ice cream....

I'm a few years older than you, and though I now live in
southeastern Massachusetts, when I was a teenager in Cleveland
a standard item was a so-called "Boston cooler". As far as
I could ever tell, it was the same as what you're calling
(and what I would probably now call) a "float". Tom, et al.--
was the "Boston cooler" isogloss a tight little band around
Cleveland, or do others know this name? (Does it still exist?
Was/is it different from a "float" in some way?)

Lee Rudolph