You're off by a year or two at best. Linus announced his kernel project on the Minix usenet group in Aug 1991.
replyIt wasn't until mid 1992 that distros started to exist, and I'd say it took a bit of time for those to be complete enough to be usable for someone with a goal other than smoke-testing the kernel on their PC.
I can say for certain that I, a complete newbie, was able to boot SLS Linux floppies in early 1993, and within a couple months I was installing Slackware to HDD.
Yeah, 1993 is when things really took off. First SLS, then Slackware, and using Slackware as the build environment: Debian.
replyYou also had SuSE, which really started as German-localized Slackware.