USS Galena was a wooden-hulled broadside ironclad built for the United States Navy during the American Civil War. The ship was initially assigned to the North Atlantic Blockading Squadron and supported Union forces during the Peninsula Campaign in 1862. She was damaged during the Battle of Drewry's Bluff because her armor was too thin to prevent Confederate shots from penetrating. Widely regarded as a failure, Galena was reconstructed without most of her armor in 1863 and transferred to the West Gulf Blockading Squadron in 1864. The ship participated in the Battle of Mobile Bay and the subsequent Siege of Fort Morgan in August. She was briefly transferred to the East Gulf Blockading Squadron in September before she was sent to Philadelphia, Pennsylvania for repairs in November.

An ironclad was a steam-propelled warship protected by steel or iron armor constructed from 1859 to the early 1890s. The ironclad was developed as a result of the vulnerability of wooden warships to explosive or incendiary shells. The first ironclad battleship, Gloire, was launched by the French Navy in November 1859, narrowly preempting the British Royal Navy. However, Britain built the first completely iron-hulled warships.