In the fairly small town where I lived, we had massive graduation parties in the 80s. It was very common. I graduated in 1985 and I had a massive house party. Most of my friends had major parties, many were on the same day. You could post on a bulletin board or hand out flyers at school before graduation if your party was "open house" meaning anyone could come. Many did this, including me. Hell, kids I didn't even know and their friends came to mine. I had hundreds of people at mine and I wasn't even in the most popular kids group, just an average kid who tried to be nice to everyone. Some of the more popular kids with money had major blowouts that went on a couple days.

Most parties in my area on grad day would start out as family gathering type of thing in early afternoon, but usually by the evening, most of that vibe was gone and it was mostly kids partying. Of course, not all kid's families could afford to have a big party, so some did not.

We (my grad class and juniors from that year) all did like you would for bar hopping - go in a group, spend some time at each party in the evening and move on to the next. You could even leave your own party for a while and go to others for an hour or two then come back, which is what I did. Some were less chaotic and catered in a hall. Others were at someone's house with a potluck and backyard party with no end time, which is what mine was... It was the best party of my life, outside of my wedding. Guests had run of the entire house and it was totally crazy. We were just winding down as the sun came up the next day.

And yep, there were kegs of beer. Quiet suburban neighborhoods, not something out in the country, like you might picture based on what I'm saying. Honestly most parents back then who I knew did not care if we drank beer as juniors and seniors in high school as long as we weren't driving. Yes they knew it was illegal, drinking age was 19 where I lived at that time, but everyone did it on the down-low at around 16 or 17 anyway, often with parental consent! The idea was that at least they know where the kids are so they let them drink at home once in a while as long as they aren't driving.

The vibe was pretty much exactly like a wedding at most of these parties, except the majority were high school kids. Most of the money from mine came from my parents and other adult relatives that came early in the afternoon. I had an aunt who was a wedding cake maker, so she made a couple beautifully decorated sheet cakes for me as her gift. Some kids would bring $10, but a lot of them didn't and it was accepted and not required. Mostly the relatives brought money gifts or in some cases an actual gift. Many kids considered the money as something they put toward college or starting their life after school if they weren't going to college. I made about $2,000 at mine.

Today, I don't see it happening that much. I didn't have kids and my relatives who did/do have kids did not have big parties, just small family gatherings, but the money gifting from relatives is still a thing.