I dunno about that, but the first Linux I installed myself, was a version of Slackware whose version-number I no longer recall, but I *do* remember that it came with the 1.2.13 kernel and was delivered on a CD from Walnut Creek.
I guess that must mean it was 1995 or something of that nature ?
We're thus nearing the date when I can say: "I've run Linux since before you where born, little one."
I -do- remember a.out vs elf being a big deal - along with getting scandinavian letters to work right on the console, which at the time required arcane magic. (and even then you couldn't generally expect it to work right in all programs)