What year was it cast?.....It should also say on the muzzle.....My reenacting unit fires an original 1862 3" Ordnance from Phoenix Iron Works....
Here's a pic of it: http://cptscott.angelfire.com/cannon.htm
We have 4 civil war canon in town, 1 is operational, restored in 2004, brass 12 lb., Cyrus and Alger I believe. The writing on this one is so faint I cannot make out much other than its cast, 476, and the PICo. It is used as an ornament, is outdoors and is begining to rust. I dont think it could be fired without some serious work being done. Im starting to work with the people in my town on trying to get some of these things looked after. The canon restored is 2004 is sheltered.