And the UK too. In the 70’s and 80’s there was a book and accompanying tape called something like ‘music and movement’. Lots of traditional music from around the globe and the dances to go with them. But our teacher really liked the square dancing so that was the one we did almost every week.
The slow dancing I remember wasn’t about groping or just pressing bodies together (though some certainly did that, when the chaperones weren’t paying attention), but even with a few inches of separation, it was still definitely regarded as more romantic than the general bopping of fast-paced dance music.
And I don’t think we ever did any sort of dancing in PE class. We did do parachute stuff, but the reason for that was that the parachute stuff was fun, but also only worked with a large group, so kids couldn’t just do it at home.
We did square dancing in grade school. I’m not sure whether it was music or PE, because the same teacher taught both.
We had a few ‘social dancing’ sessions in high school gym which resembled square dancing. Holding hands with girls had become much less objectionable in the ensuing years.
I never knew about the parachute stuff. Sounds like fun!
Oh, I should mention that I did take square dancing lessons for a while, but as an adult, because a local community center was offering it for free, and it seemed like fun and a good way to meet people. Turned out that the only other people at the lessons were retirees and nine-year-olds.
But Steve, I like nine year olds. 
There is a couple with whom I’m friends, who were very big into square dancing when I first met them, and they were in their late 20s. The husband was even a caller for square dances, and they were typically the youngest people at their dances, by a fair margin.