While not specifically indicative to The United States – but having greater success in their development and combat deployment, The ''Mortarclads'' were a type of Warship that were seen in The American Civil War of 1861-65. They were deployed mostly along river routes and on occasion for coastal attacks against Confederate fortifications. The Mortarclad was a converted vessel, more akin to a barge. It's sides were made of reinforced iron plating, in some cases as much as 3-inches thick. Overall length varied to between 150 and 225-feet and being several hundred tons displaced. Traditionally Mortarclads did not have Rigging Plans (Sails) and were steam propulsion. In some case, citing The Siege of Vicksburg, Mississippi – Mortarclads were anchored to a specific spot.
Normally no more than (2) 10-inch Mortars were erected on Deck. Whereas these could not be rotated without moving the vessel, this made their overall effectiveness somewhat difficult to assess. The Union Navy deployed as many as 30 such Mortarclads on The Mississippi River and used them in conjunction with The Battle of Mobile Bay (Alabama, 1864). The Confederacy too developed a form of Mortarclad as well. However materials and overall procurement of Mortars was difficult, with very few examples constructed.