USS New Ironsides was a wooden-hulled broadside ironclad built for the United States Navy during the American Civil War.

After the United States received word of the construction of the Confederate casemate ironclad, CSS Virginia, Congress appropriated $1.5 million on 3 August to build one or more armored steamships.

The USS Monitor was the most innovative design by virtue of its low freeboard, shallow-draft iron hull, and total dependence on steam power.

[1] A two-piece articulated rudder was fitted to New Ironsides, but it proved unsatisfactory in service as the ship became more unmanageable as her speed increased.

[10] New Ironsides had two simple horizontal two-cylinder direct-acting steam engines driving a single brass 13-foot (4.0 m) propeller.

Accordingly, the design changed while the ship was under construction to accommodate fourteen 11-inch Dahlgren guns and two muzzle-loading 8-inch (203 mm), 150-pounder Parrott rifles.

On 27 September the navy paid Merrick & Sons $34,322.06 for "extras", presumably the armored bulkheads, shutters, and conning tower not included in the original specifications.

[26] The day after New Ironsides was commissioned, she sailed for Hampton Roads where Rear Admiral Goldsborough had been requesting her since July.

He feared a Confederate sortie down the James River to attack his ships and did not believe that his armored sloop Galena and the prototype ironclad Monitor would be enough.

She was kept ready to respond to a Confederate attack with steam up while mechanics were sent to fix the recoil problems and the crew was training.

Admiral Du Pont's pilot was unfamiliar with New Ironsides' quirks, and the channel used during the attack was shallower in places than her deep draft; she maneuvered erratically and had to anchor several times to avoid going aground.

As the ship was withdrawing she anchored directly over a Confederate "torpedo" (mine) that was filled with 3,000 pounds (1,360 kg) of gunpowder that failed to detonate.

During the bombardment New Ironsides fired only a single broadside, but she was hit over 50 times in return without significant damage or casualties.

While resupplying ammunition on 8 September, New Ironsides was called to provide cover for the monitor Weehawken which had grounded between Fort Sumter and Cummings Point.

New Ironsides anchored 1,200 yards (1,100 m) in front of Fort Moultrie and forced the Confederate gunners to seek cover; she fired 483 shells and was struck at least 70 times.

The ship also contributed crewmen for the landing party that unsuccessfully attempted to seize Fort Sumter on the night of 8–9 September.

Between July and October New Ironsides fired 4439 rounds and was hit by at least 150 heavy projectiles, none of which inflicted any significant damage or casualties.

[32] New Ironsides completed her overhaul in late August 1864, now under the command of Commodore William Radford, but did not join the North Atlantic Blockading Squadron in Hampton Roads until October when her crew finished gunnery training.

She participated in a major assault in December on Fort Fisher, North Carolina, in an effort to stop blockade running into the port of Wilmington.

Though this attack was called off on Christmas Day after an extensive bombardment, the Union fleet returned to resume the operation on 13 January 1865.

New Ironsides was one of several warships that heavily shelled Fort Fisher, preparing the way for a ground assault that captured the position on 15 January.

She was decommissioned on 6 April 1865[33] and was laid up at League Island, Philadelphia, where, on the night of 16 December 1865, New Ironsides was destroyed by a fire.