<P> By 1862, navies across Europe had adopted ironclads . Britain and France each had sixteen either completed or under construction, though the British vessels were larger . Austria, Italy, Russia, and Spain were also building ironclads . However, the first battles using the new ironclad ships involved neither Britain nor France, and involved ships markedly different from the broadside - firing, masted designs of Gloire and Warrior . The use of ironclads by both sides in the American Civil War, and the clash of the Italian and Austrian fleets at the Battle of Lissa, had an important influence on the development of ironclad design . </P> <P> The first use of ironclads in action came in the U.S. Civil War . The U.S. Navy at the time the war broke out had no ironclads, its most powerful ships being six unarmored steam - powered frigates . Since the bulk of the Navy remained loyal to the Union, the Confederacy sought to gain advantage in the naval conflict by acquiring modern armored ships . In May 1861, the Confederate Congress appropriated $2 million for the purchase of ironclads from overseas, and in July and August 1861 the Confederacy started work on construction and converting wooden ships . </P> <P> On 12 October 1861, the CSS Manassas became the first ironclad to enter combat, when she fought Union warships on the Mississippi during the Battle of the Head of Passes . She had been converted from a commercial vessel in New Orleans for river and coastal fighting . In February 1862, the larger CSS Virginia joined the Confederate Navy, having been rebuilt at Norfolk . Constructed on the hull of USS Merrimack, Virginia originally was a conventional warship made of wood, but she was converted into an iron - covered casemate ironclad gunship, when she entered the Confederate navy . By this time, the Union had completed seven ironclad gunboats of the City class, and was about to complete the USS Monitor, an innovative design proposed by the Swedish inventor John Ericsson . The Union was also building a large armored frigate, the USS New Ironsides, and the smaller USS Galena . </P> <P> The first battle between ironclads happened on 9 March 1862, as the armored Monitor was deployed to protect the Union's wooden fleet from the ironclad ram Virginia and other Confederate warships . In this engagement, the second day of the Battle of Hampton Roads, the two ironclads repeatedly tried to ram one another while shells bounced off their armor . The battle attracted attention worldwide, making it clear that the wooden warship was now out of date, with the ironclads destroying them easily . </P>

When were ironclads first used in the civil war