I remember them as a kid during the 1970s. I was in Boy Scouts then and I'd go there to get canteens, jackknives and other gear for hiking/camping trips that the Scouts actually did for real back on those days.
These days, kids are more likely to think of the Old Navy clothing store (owned by The Gap) when you mention Army/Navy store.
My Scout Troop's store of choice was
I. Goldberg in Center City, Philadelphia. Several of us would make subway trips from suburbia - we'd spend hours browsing and buy a few things.
hiking/camping trips that the Scouts actually did for real back on those days.
Jamborees were also fun......