Robert Fulton
The first successful trial run of a steamboat had been made several years earlier in the United States by inventor John Fitch, on the Delaware River on August 22, 1787. Attendees included delegates from the Constitutional Convention, who were observing while taking a break from their summer-long sessions at Independence Hall. The steamboat was propelled by a bank of oars on either side of the boat. The following year Fitch launched a boat powered by a steam engine driving several stern-mounted oars. These oars paddled in a manner similar to the motion of a swimming duck's feet. With this boat he carried up to thirty passengers for hire on numerous round-trip voyages on the Delaware River between Philadelphia and Burlington, New Jersey.
Steamboats of the Columbia River
Another sidewheeler on the Willamette at this time was the Mississippi-style "Wallamet", which did not prosper, and was sold to California interests. In 1853, the side-wheeler "Belle of Oregon City", an iron-hulled boat built entirely in Oregon, was launched at Oregon City. "Belle" (as generally known) was notable because everything, including her machinery, was of iron that had been worked in Oregon at a foundry owned by Thomas V. Smith. "Belle" lasted until 1869, and was a good boat, but was not considered a substitute for the speed and comfort (as the standard was then) of the departed "Lot Whitcomb". Also operating on the river at this time were "James P. Flint", "Allen", "Washington", and the small steam vessels "Eagle", "Black Hawk", and "Hoosier", the first two being iron-hulled and driven by propellers.
"Jennie Clark", built by Jacob Kamm with John C. Ainsworth as her first captain, was placed in service in February 1855. She was the first sternwheeler on the Columbia River system. Her hull and upper works were built at Milwaukie, while her engines were built in Baltimore to Kamm's specifications, for a price of $1,663.16, and shipped around to the West Coast, which cost another $1,030.02. Kamm and Ainsworth had settled on the sternwheeler as superior to propeller-driven and side-wheel boats. Propellers were too vulnerable to expensive-to-fix damage to propellers and shafts from rocks and other obstructions in the river. Sidewheelers were too difficult to steer and needed expensive dock facilities.