Who invented the steamboat?

Robert Fulton was the first to COMPLETE the first steamboat
Robert Fulton.

Robert Fulton did not invent the steam boat. John Fitch invented it, but he died before he fixed the problem in the engine. Robert Fulton is given credit for it because he finished John Fitch's design, and tweaked the engine.
She was built by the wealthy investor and politician Robert Livingston and inventor and entrepreneur Robert Fulton. Source: Wikipedia "North River Steamboat" page