I read up on some things concerning the Abiball, and while Wikipedia had a general idea of some things (it's an event for Gymnasium graduates, people wear fancy clothes and have drinks, and there is also the Abifeier, which is student organized and makes fun of teachers), it skipped some details I'm looking for, which are:
1. I read that parents may accompany students to the Abiball; is that true?
2. Were they done in most schools back in the 70s in the former West Germany (I'm looking at Hesse)?
3. Do other secondary schools have similar dances?
4. Are there dances throughout the year at German schools the way there are sometimes at American schools?
Googled: German Abiball, German Abiball 1970s
Edit 2: Thank you for all the help so far. I have one more question:
5.I was looking for my MC to pick up some swearing from his mother. I'm not looking for anything too vulgar, because she's middle class, I'm just looking for some very basic things.
Edit 2: Put up after I put answered, d'oh. I wondered how long the NY's fireworks displays have been regularly done? Would they have been held in the 60s-70s?