I had hoped to see a friend next month and bring him a local bourbon.  Not going to happen.  What are the legalities of shipping it?  I'm finding conflicting info online and at the different carrier's websites.

Agreed to this.   When I was a mail carrier, I had things leak in my car, which was not cool.  

I always told people who were going to ship any liquid, to find a tight-sealing plastic bag that will contain the entire bottle, make sure it's sealed completely, and pack the bottle, if it's glass, in a box of peanuts, and put that inside another box of peanuts.  This makes shipping expensive, but if they are shipping, say, homemade relish or canned tomatoes to their kid at college, the gift is important because it has meaning, so it makes sense to pack it especially carefully.  also they should be sure to put "Food" on the outside of the box, and "perishable" and when the clerk asks them if the package contains anything "fragile, liquid, perishable, potentially hazardous, or lithium batteries, "  They should answer yes, there is liquid and it is perishable.  

This helps the post office know how to handle foods and liquids, and ensures the homemade, or expensive store-bought gift (body lotion or fancy shampoo, etc) gets there safer.

No matter what you are shipping through the postal service, you should take extra care to protect glass, foods, or liquids.  This protects everyone, including the carrier and her vehicle.