John-

The intriguing thing about "Whiskey Johnny" et al to me is the reference to "whiskey" rather than "rum." Although the Scots manufactured whiskey, I believe it's the North Americans that made the beverage a national drink and a popular term. And I suspect the Gold Rush crowd were particularly inspired to extoll its virtues in verse.

Oh, and congratulations for initiating a scholarly thread that now has chalked up 500 posts (if someone hasn't just beat me to it!).

Cheerily,
Charley Noble