Which Slam had the most locals participating?

Which Slam had the most of its own players playing in the main draw? I remember around Australian Open 2000 had 16 Aussies which is a lot compared to now, what? 5-6 players I think?

Conversely, what's the most ever for each Slam? I'm sure Wimbledon had the least amount of players and least talented as well.

Has to be RG? Or maybe USO, there are always plenty of young kids/old veterans getting WCs

If you want to go back to the 70s I wouldn't be surprised if the US had 40 or so in the Us Open.