Oliver Evans (13 September 1755 – 15 April 1819) was a United States inventor.
The first automobile patent in the United States was granted to Oliver Evans in 1789. Later, in 1805, Evans demonstrated his first successful self-propelled vehicle, which not only was the first automobile in the USA but was also the first amphibious vehicle, as his steam-powered vehicle was able to travel on wheels on land and via a paddle wheel in the water.
The device for which Oliver Evans is best-known today is his Oruktor Amphibolos, or "Amphibious Digger", built on commission from the Philadelphia Board of Health. The Board was concerned with the problem of dredging and cleaning the city's dockyards, and in 1805 Evans convinced them to contract with him for a steam-powered dredge.
No drawings of the device survive, and the only evidence for its design come from Oliver Evans' own descriptions, which are contradictory, and most likely exaggerated. He describes the vehicle as a 30-foot long 15 ton scow, powered by a 5 horse-power steam engine. For a demonstration of his long-held beliefs in the possibility of land steam demonstration, Evans mounted the hull on 4 wheels and may have connected the engine to them, to drive it through Philadelphia streets on the way to the river. The small size of the engine, the large size of the vehicle, and the lack of any contermporary evidence other than Evans' own writings for it make this seem unlikely. Evans claimed that his dredge was the first self-powered amphibious vehicle, as well as the first self-powered land vehicle in the United States (steam powered automobiles had already been used earlier in France and Great Britain). The Oruktor Amphibolos was never a success as a dredge, and after a few years of sitting at the dock was sold for parts.