Ironclad (Civ5)/Civilopedia

Although visionaries had been dreaming of machine-powered armored vessels as far back as Leonardo da Vinci, ironclads first saw widespread use in the American Civil War in the mid 19th century. The first true ironclad battle was in the American Civil War in 1862, between the Union's Monitor and the Confederacy's Virginia (also known as the Merrimac). The battle raged on for four hours, with both vessels' cannon hammering away at each other to little effect, and the fight pretty much ended in a draw. However, the effect of the battle on the world was profound. In a single morning of inconclusive fighting these ponderous and clumsy vessels - able to move against the wind and mostly impervious to the cannon of the day - made every world's navy obsolete.