There is an episode of BBS The Documentary from @textfiles that is about FidoNet, which was... almost, kind of, like an early federated forum thing (basically it let people on BBS server 1 could talk to people on BBS server 2). The tech details don't line up exactly but I was struck watching it a few years ago at how the social dynamics of admins of different BBSes mapped pretty perfectly onto fediverse admins.

Anyway if you want to feel like time is a flat circle: https://www.youtube.com/watch?v=Ng0NE4lDP2U