Borrowed from the allexperts dot com site.
I have the time today to follw-up and give you a little history on the Presbyterian Highball.
The original drink is not an alcoholic beverage at all, it's just soda. I think it goes back about 50 years or so. When people were having "parties" and neighbors were invited, there was always a few Presbyters and/or non-drinkers that were invited too. Presbyters do not consume alcohol,coffee,blah,blah,blah. So, to be social, someone( I suspect a Bartender) came up with a mix of Ginger Ale and Club Soda that "looked" like a Rye and Soda. That way they could hang at the party and "blend" with something that looked like a drink yet not consume Alcohol. If you make one of these N/A drinks some time and set it next to a 7&7 or Rye & Ginger, you'll see how much they look alike.
Somewhere along the line a partier must have gotten one of those by accident and just added some Rye Whisky to "improve" it,lol. Thus we have the Presbyterian Highball! And, as I'm sure you've been able to figure out, it's a less sweet drink than a Rye and Ginger is.
You'll find that most people that order one will simply say; "I'll have a Press/Presbyterian please" or "I'll have a Rye Press/Presbyterian please". And, most often it'll be someone a little more "mature" than a 20-something.
Ok Jarod, I'm feeling better now that I've given you the rest of this answer. I'm sorry I didn't have much time yesterday.
I'm looking forward to hearing from you at http://www.askyourbartender.com
Here's looking forward to talking to you again soon,