Editorial use only John Ericsson (1803-1889), Swedish-US inventor and engineer. Ericsson served in the Swedish army as an engineer for six years, then resigned to become an inventor. He moved to England in 1826, where he designed the first screw propeller for ships. This made steam propulsion possible for naval vessels. In 1839 he moved to America, designing a screw-propelled ship for the US Navy, the USS Princeton. In 1861 he built his first 'ironclad', the Monitor, which took part in a US Civil War battle that signalled the end of the wooden battleship. 1860s photograph from the Charles D. Fredricks company in New York, USA.