If it's only about the origins of the Federation as suggested in the OP, then the only answer is Archer.
I think Kirk could be viewed as famous from a 26th-Century perspective by being the most well-known captain of the 23rd-Century. Ditto for Picard in the 24th-Century. Sisko's contributions to history is connected to the discovery of the Bajoran Wormhole and as a hero of the Dominion War. Janeway could also be considered historically important for bringing back slipstream drive from the Delta Quadrant and the unprecented number of first contacts she made there (which could be a big deal in the 26th-Century).