I believe this is a South Carolina Civil War button. The item "FANTASTIC CONFEDERATE CIVIL WAR D GUARD BOWIE KNIFE" is in sale since Wednesday, August 12, 2020.
This item is in the category "Collectibles\Militaria\Civil War (1861-65)\Original Period Items\Other Civil War Original Items". The seller is "mul298qdz" and is located in Broad Brook, Connecticut. This item can be shipped worldwide.