who created the first useful steamboat and what was it useful for?

The era of the steamboat began in America in 1787 when John Fitch (1743-1798) made the first successful trial of a forty-five-foot steamboat on the Delaware River on August 22, 1787, in the presence of members of the Constitutional Convention. Fitch later built a larger vessel that carried passengers and freight between Philadelphia and Burlington, New Jersey.

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It piled rivers and lakes.