This is a cool piece! It is the Civil War case shot Schenkl shell. That means that it is the style with the case shot balls that would have spread out when the shell exploded acting as a shot gun style blast. The Schenkl pattern is one of the most distinctive patterns of cannon shells of the Civil War. They have the tapering back with the ribs as you can see in the pictures. This one is attractive excavated condition. At the top of the shell it has the brass style Schenkl percussion fuse. On the top of the fuse you can still see some of the markings including the 1861 patent date as well as the Schenkl marking. The verbal history that accompanied this shell is that it was recovered in Petersburg, Virginia which is just right outside of Richmond. This area was one the last battles before Richmond fell into the hands of the Union Army. It has been cleaned and disarmed for display and preservation.