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.
Ironclads were first used in warfare in 1862 during the American Civil War, when they operated against wooden ships, and against each other at the Battle of Hampton Roads in Virginia. Their performance demonstrated that the ironclad had replaced the unarmored ship of the line as the most powerful warship afloat. Ironclad gunboats became very successful in the American Civil War.