Yesterday I mentioned the pair of 6-pdr bronze field guns on display at the National Guard Memorial Museum.
The two guns were employed by the Massachusetts state militia between 1790 and 1810. The plaque beside the guns suggests a connection with Revere Copper, of Boston, Massachusetts.
The breech of the guns resembles that of the Revolutionary War period bronze guns. Multiple moldings support a raised base ring. Notice the cut through the top of the ring, likely used to align sighting.
The vent is an inset hole instead of the keyhole shape of some other weapons of the period. In front of the vent is an astragal ring. The number in front of the vent appears to be post-casting and is probably an administrative tracking mark.
The trunnions lack any markings. Typical for American guns of this period, it also lacks rimbases.
The reinforce ends with a stepped ring just past the trunnions.
The muzzle profile looks familiar in many respects to later bronze 6-pdrs. The muzzle swell flares a bit more, however. The chase ring astragal separates the muzzle from the chase.
The muzzle face has no markings to aid identification of the gun.
Indeed the only identification of this piece is between the trunnions – an Algonquian figure similar to that incorporated with the state seal.
Overall, these two 6-pdrs are smaller than most Army regulation patterns. Dimensions are closer to that of the Cadet Guns cast a half century later.
These guns were not employed during the Civil War, save perhaps administrative or ornamental tasks. However the two guns are examples of early American 6-pdrs. These also provide examples of the various non-standard guns used by local and state militias in the first half of the 19th century.
To the Sound of the Guns 
Do these cannons typically have inscriptions? I found what I believe to be part of a cannon near a ship wreck in the Delaware Bay. There is mystery surrounding the wreck. Some say it is the Spanish ship Brig Newbern lost by Captain John Cushing heading to Philadelphia in the 1800s. What we found clearly has the inscription CF which I thought might be for Columbia Foundry. I can send a photo to anyone interested. Thanks!