Michael Sussman was instrumental in establishing which species founded the Federation. “My phone rings and Brannon [Braga] says, ‘Mike, real quick - who are the founding species of the Federation?’ What flipped through my mind,” recalled Sussman, “was that it had never been established, but there had been a lot of fan speculation going back to ‘Journey to Babel’ that many of those races - the Tellarites, the Andorians and the little gold guys - were among the founding members. For that quarter of a second I’m thinking, ‘What do I tell him? If I say it’s never been decided he might make up a couple of new races and that might set certain people off’. So I basically lied to him and said ‘Oh yeah, it’s Andorians and Tellarites.’ He put it in the script and now it’s canon!” (Star Trek: The Official Starships Collection, issue 37, p. 15)

https://memory-alpha.fandom.com/wiki/United_Federation_of_Planets#History