Steamboats are ships in which the primary method of propulsion is steam power, typically driving propellers or paddlewheels.
Steam engines were developed and adapted in the late 18th century for use on ships, but did not become widely used until the early 19th century. In 1811 the first in a continuous line of river steamboats left the dock at Pittsburgh to steam down the Ohio River to the Mississippi and on to New Orleans. From then on growth in their use was rapid on United States rivers, and steamboats gradually replaced sailing ships for commercial shipping through the latter 19th century. Steamboats in turn were overtaken by diesel-driven ships in the second half of the 20th century.