Trading cards were certainly a popular part of my youth. I was born in the late 1940s, just a few years after World War II. We were not affluent by any means, but trading cards were affordable. It was a different time before electronics took over, so we had to amuse ourselves, and trading cards were a way of doing so.
I recall trading cards being available at a corner store less than a block from where I lived. We would walk to the store with one cent and buy a package that contained one trading card and a nice size piece of bubble gum. The card would have a pink rectangle imprinted on it from the gum. If we had five cents, we could buy a larger package with six trading cards and one larger piece of bubble gum. This was better since the gum was not what we wanted. And the five cards below the top one were not marked by the bubble gum.
The cards were TOPPS cards, and depending on the season might be baseball or football themed. We preferred football cards. We tried to get an entire set, but there were always a few we could not find. Since the cards were numbered we could determine the size of the set. Our favorites were team cards, single cards of entire teams.
We had no such thing as Pokemon back then.