Originally Posted by
Velo Vol
In the ocean, mainly. Civil War cannon didn't get buried in battle. Artillery wasn't like WWI or WWII.
Retreats were often less than organized, and pursuits might not bother to pick up after the gun crews as they ran. Plus, if the gun carriage was damaged, someone would have to fix it to bring that gun along.
Also, you need at least one horse per gun. Kill the horses, and the guns go nowhere.