The ship was built to a design by the Chief Naval Constructor, John L. Porter, based on his earlier work on the ironclad, retaining the traditional curving ship-type hull, but with flat ends to the casemate. As usual for Confederate ships, dimensions vary slightly between sources. The plan showed an overall length of 174feet and a length between perpendiculars of 150feet with a maximum beam of 43feet, a moulded beam of 32feet and a depth of hold of .[1] The ship's draft was 12 feet,[2] [3] although Canney says that Palmetto State drew 14feet of water. She was fitted with a hatch for the pilot above the steering wheel for ease in issuing orders to the helmsman and engine room abaft the funnel even though it blocked the pilot's forward vision.[4]
The propulsion systems of the Richmond-class ironclads were different for each of the ships, often depending on what could be sourced locally. Palmetto States pair of single-cylinder, direct-acting steam engines were taken from the gunboat serving in Charleston. They used steam provided by a pair of horizontal fire-tube boilers built by the locally based Cameron & Company to drive a 8or propeller. The boilers were probably 11feet tall, 10feet long, and 6feet wide. The ironclad had a speed of 6kn7kn[5] and a crew of 120.[4]
Palmetto State was initially armed with one 7inches Brooke rifle on a pivot mount at the bow, a 6.4inches Brooke rifle on a pivot mount in the stern, with two 8adj=onNaNadj=on muzzle-loading smoothbore guns on the broadside.[4] The ship was later equipped with a spar torpedo on her bow in 1863.[6] The Dictionary of American Naval Fighting Ships merely states that her armament consisted of two rifled guns and two smoothbore 9inches guns.[2] Naval historian Raimondo Luraghi states that the ship was armed with two Brooke rifles and two smoothbores,[7] Naval historian Donald Canney says that a January 1865 report shows the ship equipped with ten 7-inch Brooke rifles, four on each broadside and one each in the bow and stern. He does not believe that it is accurate because the addition of so many additional guns would require rebuilding the casemate and would strain the ship's hull with so much extra weight.[4]
Her casemate armor was 4inches thick, backed by 22inches of wood, while 2inches of iron armor was used everywhere else.
Named for the nickname of South Carolina,[8] Palmetto State was laid down in January 1862 by Cameron & Company at their shipyard in Charleston, South Carolina.
Before dawn on 31 January 1863 Palmetto State and her sister ship crept through thick haze to surprise the Union blockading force off Charleston. Taking full advantage of her low silhouette in the darkness, the ironclad steamed in under the guns of the Union gunboat, ramming as well as firing heavy shot point-blank into her hull. Completely disabled, with cannons that could not be depressed low enough to fire at Palmetto State, the Union ship was forced to surrender. The ram then turned her attention to, firing several shells into the blockader. Her steam chests punctured, Keystone State lost all power and had to be towed to safety. A long-range cannon duel between the Confederate rams and other Union blockaders then took place, but little damage was inflicted by either side before Palmetto State and Chicora withdrew to safety within Charleston Harbor. The attack by the Confederate rams caused the temporary withdrawal of the blockaders from their inshore positions and led to the claim by the Confederate government, unsuccessfully advanced, that the blockade of Charleston had been broken.
Palmetto State also joined in the defense of Charleston during Admiral Samuel Francis du Pont's unsuccessful 1–7 April 1863 attack on the harbor forts. Her officers and men were cited for rendering valuable services on the night of 6–7 September 1863 during the removal troops from Fort Wagner and Battery Gregg.
Palmetto State was later set afire by the Confederates to avoid capture upon the evacuation of Charleston on 18 February 1865.