Pittstamp, welcome to the forum

. I suspect this thread might have turned into something you did not ask for. Going back to your original post I think you nailed the essence yourself of what stampcollecting should be for a nine year old: "just because it is fun". You also mentioned the economical aspect. The cheapest start is a plain worldwide mix. It will offer a kid lots of fun, regardless of all the 'grown-up-aspects'. Then you can only hope the kid will happen to enjoy the history part of it as well, US or not.
I have introduced all my 4 kids into WW stamps. Each of them found something different that attracted them, only my 8 year old prefer stamps from his own country. But they all have had fun and learned a lot without any cost to me at all, as they have simply dived into my leftovers. I hope your kid will do the same
