I would check a period manual for Civil War era artillery ammunition. Percussion fuses were experimented with as early as the late 17th century. However, they were unreliable and were generally not used because of that unreliability. Percussion fuses were experimented with in ca 1840s and might have been available for the American Civil War. They were later called point-detonating fuses, as the round would explode when it either hit the ground or the target. However, for the round common shell it was difficult to ensure that the fuse would actually hit the target because of the rotation of the round after firing.