The rivers of America have been used for transportation as long as man has been here. As the Westward movement of the new Americans began, the Ohio River and its tributaries were full of flatboats carrying entire families and all their belongings down stream to their new homes. Seeing a market for all sorts of goods, men built flatboats and loaded them with items needed by the settlers, and sold them as they proceeded down the river. Since it was almost impossible to get the flatboats back up the river, and lumber was needed by the settlers, the boats were also sold. The boats were taken apart and the lumber used for building homes, stores, barns, etc. Later, the keelboat was designed, and although with great difficulty, it could be poled, pulled, and sailed back up stream to be used again. With more and more settling down stream, more and more goods and supplies were required. A better means of transporting them was necessary. When there is a need, someone will fill it. Robert Fulton and Nicholas Roosevelt made the first big step with a steam powered boat. The paddlewheel boat was invented. It established the inland river transportation system as one of the greatest assets of the United States.