
A howitzer is a short-barreled artillery piece designed to throw large projectiles at high trajectories. In Federal service, nearly all 12-pounder howitzers had been replaced by the 12-pounder Napoleons. The Confederates, having a shortage of field pieces, maintained them in their arsenal. Howitzers fired solid shot, spherical case, and cannister.
Bore Diameter 4.62 in (11.73 cm) Tube Material Bronze Tube Length 53 in (135 cm) Tube Weight 788 lb (357 kg) Powder Charge 1 lb (0.45 kg) Range (5° Elevation) 1,072 yd (980 m) At Gettysburg 2 (USA); 26 (CSA)
http://einstein.human.cornell.edu/ACW/arty/12howitzer.html