My uncle Matt told me that this was a US Civil War cannon ball. I truly belive it is a cannonball, but aside from his claim, I have no way to verify what era this cast iron cannon ball is, but I have no reason to doubt Uncle matt. In any case, this 4 lb cast iron cannon ball has a diameter of 3 inches. It is most definitely weatd and definitely old. This wonderful early war relic will make a great addition to any vintage civil war or early ammunition or military cannonball collection.