At the start of the Civil War, both in the North and South, some militia companies wore Dragoon hemets. This style of headgear had been worn for decades by milita companies in America.
Although the helmets were getting a bit dated by the start of the Civil War some units still used them. One can see that moderm uniform artist like to try to include them in Civil War uniform books.
It is possible some militia units wore their Dragoon helmets off to war. I was wondering if there are examples of them being worn in combat.