At the end of the war ordinance of all kinds was returned to ordinance depots. Into the 20th Century a surprising number of Civil War cannons lingered in deep storage. The Rock Island Arsenal still has a collection of CSA artillery.
Here is a link to a unique CSA rifled cannon received from Rock Island. Bet nobody has seen one of these:
Story County's Historic Civil War Cannon
www.storycountyiowa.gov
There was a process where local governments, civic organizations & clubs could apply for cannons. The ins & outs were predictably convoluted sometimes, but it was routine to release inventory for public display.
Link to Rock Island Arsenal:
( You gotta admit this a cool looking link. )
One of the pleasures of volunteering at a black powder park is getting to poke around the maintenance area where visitors never go. There are some real curiosities waiting to be displayed to the public.
I realize that it has a "to shepherds sheep are different" sound to it, but the Army & Ordinance Bureau are very different animals.
Note: The link is an excellent citation you will want to save. It is rare to find one this good on this topic.