There were several cannons used in the civil war, all of which were very effective. These cannons include the 6 pounder Gun, 12 and 24 pound Howitzer, 10 and 20 pound Parrott rifle, 3 inch Ordnance rifle and the infamous 12 pounder Napoleon cannon.
At the time of the civil war, there was a very important technological advance which was deemed in advance for the time period. The ability to produce rifled barrel field artillery which increased accuracy, distance and range. There were two categories the smooth-bore cannons used which were guns and howitzers. This was used for firing at higher trajectories and shorter ranges.