Oliver Evans was born in Newport, Delaware, on September 13, 1755, and as a young man was apprenticed to a wheelwright. At 22 he invented a machine for making the carding teeth used in the textiles industry. Two years later he went into the flour-milling business with two of his brothers. While working at the flour mill, he invented the grain elevator, conveyor, drill, hopper boy, and descender. These inventions essentially automated the flour-milling process to the point that the mill could be run by one person. In the late 1780s the legislatures of Maryland and Pennsylvania granted Evans the exclusive right to the application of these improvements, and the U.S. Congress granted Evans U.S. patents for his flour-milling inventions in 1790. His was only the third patent granted by the U.S. government.
Around 1800 Evans refined the steam engines of his day, developing perhaps the first steam engine constructed on the high-pressure principle. Earlier he had sent copies of his plans to England, where Richard Trevithick, who is often credited with the invention, had access to them. Although Evans had been working on plans for a steam-powered carriage, he adapted his high-pressure steam engine to further improve the milling process, which previously had been for the most part powered by water wheels.
In 1803 and 1804 the Philadelphia Board of Health commissioned Evans to build a steam-powered dredger, the first to be used in the United States. The dredge consisted of a small steam engine and the machinery to raise the mud from the Schuylkill River. It was powered to move on land over wheels and in the river by means of a paddle wheel. Evans named his craft the Orukter Amphibolos, or amphibious vehicle, and it is considered to be the first instance in the United States in which steam power was used to propel a land carriage. He urged that his idea be adapted to move vehicles on rails of wood or iron and, although he lobbied for a railroad to be built between Philadelphia and New York, the country's first commercial railroad track was not laid until the early 1830s, years after Evans's death.
Throughout his life, Evans refined the steam engine and initiated innovative manufacturing techniques. While he failed to develop his Orukter Amphibolos into a true steam-carriage, or a true paddle wheel boat, Evans long maintained that he very well could have created these conveyances. He grieved that the credit had gone to other inventors.
In 1797 Evans published the details of his early inventions in a book entitled The Young Millwright and Miller's Guide. Another Evans book, The Young Engineer's Guide, was published in 1805. Both works were translated into French and published in Paris in the early 1800s. Oliver Evans died in New York City on April 21, 1819.
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