The Honourable Company of Horners are folks who study and make objects out of cow or buffalo horn. Most of us concentrate on powder horns including replicating of ornately carved French & Indian War map horns (you had the map placed the horn to illustrate where you're going to be at or to show where you've been-the latter mostly served as a souvenier). Other folks use horn to make spoons, drinking cups, bowls, fans, combs, dice, etc.
One fellow had a horn he picked up in New Mexico. It was relief carved with a picture of a man dancing with a senorita. The words were in Espanol (Spanish) and he hoped to get it translated one day. I pulled out the cell phone, spoke with the receptionist at my work place and she translated it. It said something like, "I hope you catch all my contents, and fill me with moscatel, brandy and bourbon, and keep me with you always Tom Mc Nut." It was a horn for carrying booze!
We even had a telephone interview with an author who wrote a book on the use of horns in 18-19th Century England. It was a book she didn't want to write but her husband and then a curator pressured her.
We had a talk on blowing horns too (music horns). Before the telephones, many folks in the Appalacians called their neighbors by horn signals. Each horn had a peculiar sound that distinguished it from one another and everyone knew everyone else's horn. Each family had certain horns for certain reasons. One could be used to call in the cattle (as they do in Chihuahua, Mexico today) or to call everyone in for supper (Ma's horn). No one touched Pa's hunting horn as it was used by Pa to summon his hunting buddies for coon hunt (or some sort of critter kill). The subject of blowing horns is largely unexplored and our speaker is leading the research into that area.
Powder horns weren't really used by the Civil War soldier unless he was a civilian scout or bushwhacker. It is possible for a sharpshooter with a target rifle to have a horn, but it is more likely that anyone with the money for a target rifle would carry his powder in a flask (which were handier if they had a spring loaded spout).
BTW, I got involved into horns as I became more involved in the blackpowder sharpshooting and riflebuilding.
Here's a link to the Honourable Company of Horners.
http://hornguild.org/ I've only heard one joke about the "horn ny" folks once during the conference.