1765-1815. US engineer and inventor who designed the first successful steamships. He produced a submarine, the Nautilus, for Napoleon's government in France 1801, and experimented with steam navigation on the Seine, then returned to the USA. The first steam vessel of note, known as the Clermont, appeared on the Hudson 1807, sailing between New York and Albany. The first steam warship was the USS Fulton, of 38 tonnes, built 1814-15.