The first edit to Wikipedia happened twenty five years ago , on 15 January 2001. It was started by some folk at a company called Bomis, where I worked in 2000 and 2001. Here’s a photo I took in August 2000 of the staff at that time:

Standing, L–R: Tim Shell, Christine (Rohan) and Jimmy Wales, Terry (Foote) O’Connor, Jarod Pappas-Kelly, Liz Campeau, Rita Sanger (this photo was from before they married, but I don’t remember her maiden name), Jason Richey, Toan Vo, and Andrew McCague.
Seated, L–R: Jeremy Rosenfeld, Larry Sanger.
I blogged a bunch of stories from back then a couple of years ago, if you’d like to read more about what it was like.