Now, when I say "we did very little sandboxing back in the day" I'm referring to the groups I played with back in junior high school, high school and college. Heck, when we first started playing, we didn't even have a setting - just dungeon crawl to dungeon crawl. I guess we would call his "episodic gaming" these days (thank God for Dungeon magazine.)
Heck, even when we had the World of Greyhawk folio and adventures like Temple of Elemental Evil, it's not like the players roamed around looking for adventure. The DM either had a dungeon he'd mapped out or a module he bought, and that was the adventure for the night. The world map was just to point out where it took place;.
The few times the wilderness became part of the adventure, it was usually because it WAS part of the adventure.
I didn't start to try and sandbox (not that we called it that) until the first Forgotten Realms boxed set, as that was full of hooks and locations. Even at that, it was more like story arcs than a sandbox. Sure, the party could go where they wanted, but they were well trained and pretty much stuck to the beaten path.
It wasn't until my group was down to three players for a while in the early 90's that we fully embraced sandboxing. Spacemaster was the ruleset, and my two players found adventure or adventure found them, with little more than some plot hooks and a desire to get into trouble. We had a blast, and when our full group returned, it was to play Rifts and Battlelords. Now, somebody else was running the sandboxes.
I'm going to guess for my first 10 years of gaming, it was mostly episodic play.
Was sandbox gaming really that big a thing in the early days, or is it something that found it's place in later years, with the advent of numerous published campaign settings?
Just idle curiosity on my part...