Fitch's steam boat. Historical engraving of John Fitch's steam boat. This is thought to have been America's first steam boat. It was demonstrated to the Constitutional Convention on the Delaware River at Philadelphia in 1787. Steam power drove a bank of paddles, which powered the 14 metre long boat. Although this model was a commercial failure, later models he built, which introduced the paddle-wheel, were successful. He owned the sole right to operate steam boats in the states of New York, Delaware, Pennsylvania and New Jersey. He was granted a patent for his designs in 1791. His boats carried both passengers and freight, and became the first steam boat line.