Because of improvements in naval artillery and ammunition in the 19th century CE, warships needed better protection than wooden hulls offered. Ship builders therefore began adding iron plates to the above-water sides of their ships, and the ironclad steamships were born. The French launched the first seagoing ironclad, La Gloire, in 1859. The first battle between ironclads occurred in 1862 during the American Civil War when the CSS Virginia fought the USS Monitor inconclusively for four hours. The Monitor featured a steam-driven gun turret that sat on a flat armored deck. Designed by John Ericsson as a coastal and riverine warship, the Monitor sank in a storm off Cape Hatteras at the end of that year, but her sister ships performed admirably in the US Navy's blockade of Southern ports.