Found this today in West Virginia on an old farm. She was about 8" deep I'd say. I found a token of some sort as well that I will post in the 'What Is It?' section.
You've found a remarkable coin. The surface condition is incredible for an older ground-found copper coin! You might consider using Renaissance Wax to preserve your coin. Some of the most respected TNET posters swear by it. It is a bit expensive, but if that was my coin I'd want to give it the best treatment I could give it. Congratulations.
Great coin! Congrats!
Terpfan is right on the wax. After cleaning with a light brush and soap, let it for a few days in destilled water to remove all salts from the ground wich are left. After completly drying give it a coat wax and polish it with a soft cloth.