License Granting the Marrietta Steam Mill Company Use of an Oliver Evans Patented Steam Engine, 1812

In 1804, Oliver Evans received a patent for a high-pressure steam engine -- a radical departure from the early low-pressure engines operating in the United States at the time. Evans found commercial applications in the flour-milling industry, where some of his other innovations had already been influential. One of Evans' patented engines was installed in a steam flour mill in Marietta, Ohio in 1811.