The definition of ironclad is to take an object that is not made of metal and plate it in metal. The Civil War took that idea to the extreme by plating ships in metal. Although the first ironclad ships were mostly normal 19th century 40 foot long ships cased in iron and steam powered, the Civil War ironclad ships were very differently shaped. The two main shapes for ironclad ships were the monitor, a low to the ground, small ironclad ship with a single swivel turret, and the frigate, a ship with slanted sides that were used to protect the cannons used by the Confederate Army. There were also city class ironclad ships used on rivers. These ships made a big difference in the war by giving ships the ability to survive multiple cannon hits.