[Chat] ...Dressed to the Nines ('s)...

[arjay]

Chaz-ville,

...He was dressed "to the Nines (9's)"...

Does anyone know the meaning and derivation of this of this expression?  It 
seems to be popping up all over the place and no one can give me the 
background of it, and why it means what they suppose it means.

The web said it was early slang and therefore impossible to know for sure.

All of us collectively in CV know everything there is to know.

So what does it mean, and more importantly why?

Arjay