20 points
According to this, the first was Boot-Root from Torvalds himself in 1991. The oldest that are still around are Slackware (July 1993) and Debian (Aug 1993).
I wonder if someone could still install boot root? I’m not a techy person, but I’d watch the hell out of that YouTube video!
3 points
Sadly, I did not find Boot-Root 1991 but found these:
https://archiveos.org/linux-from-nascent/
And boot-root 2002: