A flatboat is a rectangular flat-bottomed boat with ^{[notes 1][1]} square ends used to transport freight and passengers on inland waterways. The flatboat could be any size, but essentially it is large, sturdy tub with a hull.

A flatboat is almost always a one-way vessel, and is usually dismantled for lumber when it reaches its downstream destination.^{[notes 2]}

1. ↑ NOTE: "[bracketed]" wordings in the quote below are notes added to clarify

   There were a variety of specialized flatboats [eventually developed] to ship cargo to world markets. Some [later, meaning c. 1815–20, after steam boats became common] flatboats were built with raked bows to be used on return trips alongside steamboats, serving as 'fuel flats', first hauling wood, then coal. These flatboats with raked bows evolved into coal boats. (Later,) Coal boats were tied together in fleets to be pushed by steamboats. Those coal boats evolved into the steel barges of today (plying the rivers servicing the coal fields of the Ohio River watershed).

   —Nancy Jordan Blackmore, Janes Saddlebag

2. ↑ Nancy Jordan Blackmore (2009). "Ohio River Info and History". Big Bone Lick Historical Society, Janes Saddlebag. Archived from the original on June 6, 2011. Retrieved 2010-11-30. The flatboat was the cheapest of the many types of boats used and became the standard conveyance for families moving west. All of the boats in this period were hand-powered, with poles or oars for steering, and usually floated with the current. They were not intended for round trips since the settlers used them only to get to their new homes and then broke them up for their lumber.

1. ↑ Nancy Jordan Blackmore (2009). "Flatboat History". Big Bone Lick Historical Society, Janes Saddlebag. Archived from the original on September 19, 2011. NOTE: "(parenthesized)" wordings are notes added to clarify

   There were a variety of specialized flatboats (eventually developed) to ship cargo to world markets. Some (later, meaning after steam boats became common) flatboats were built with raked bows to be used on return trips alongside steamboats, serving as 'fuel flats', first hauling wood, then coal. These flatboats with raked bows evolved into coal boats. (Later,) Coal boats were tied together in fleets to be pushed by steamboats. Those coal boats evolved into the steel barges of today (plying the coal fields of the Ohio River watershed).