Dictator: The 13-Inch Mortar of Petersburg
In 1864 a 13-Inch Seacoast Mortar, Pattern 1861, was used by the United States Army in the siege of Petersburg. The mortar was mounted on a railcar - named the Petersburg Express - and used against Confederate fortifications. The fame of this heavy mortar may be greater than it's impact upon the siege. Whether the "Dictator" is among the approximately thirty 13-Inch Mortars which survive to the present is a matter of conjecture.
24-Pounder Dahlgren Boat Howitzer at Petersburg, Virginia
24-Pounder Dahlgren Boat Howitzer Number 388 is displayed at the Petersburg National Battlefield. According to the research reflected in Olmstead et al., this particular boat howitzer was aboard USS Granite City when that ship was captured by Confederate infantry and artillery at Calcasieu Pass, Louisiana. I do not know what subsequent Confederate service the howitzer saw nor what brought it to Petersburg.
The 32-Pounder of 32 Hundredweight at Petersburg
A 32-Pounder of 32 Hundredweight of the type manufactured for the US Navy beginning in 1846 for use as the main battery aboard smaller sloops is displayed at Petersburg National Battlefield. The 32-Pounder of 32 Hundredweight is a chambered cannon - meaning the chamber in the barrel where the propellant charge is placed is of smaller diameter than the 6.4-Inch diameter of the main portion of the barrel.
30-Pounder Parrott Rifle at Petersburg
US Army 30-Pounder Parrott Rifle Number 227 (manufactured in 1863 at the West Point Foundry, 4,155 Pounds as manufactured) is displayed at Petersburg National Battlefield.