It is a US Model-1841 12-pounder Field Howitzer ...and (obviously) made of bronze. Total barrel length 59.6 inches. This one appears to have the Georgia State Seal atop the barrel, indicating it is one of the two made in September 1854 by Alger for that state. Both were issued to the Georgia Military Institute ...which no longer exists, and that probably explains why this one is now located at the State Capitol.
Regards,
Pete