File:Raddampfer luzern small.jpg|right|thumb|240px|Paddle steamers — Lucerne, Switzerland.

The term steamboat is usually used to refer to smaller steam-powered boats working on lakes and rivers, particularly riverboats; steamship generally refers to larger steam-powered ships, usually ocean-going, capable of carrying a (ship's) boat. The term steamwheeler is archaic and rarely used.

Steamships gradually replaced sailing ships for commercial shipping through the 19th century

Screw-driven steamships generally carry the ship prefix "SS" before their names, meaning 'Steam Ship' (or possibly 'screw-driven steamship'), paddle steamers usually carry the prefix "PS" and steamships powered by steam turbine may be prefixed "TS" (turbine ship). The term steamer is occasionally used, out of nostalgia, for diesel motor-driven vessels, prefixed "MV".

Early development

In 1736, Jonathan Hulls took out a patent in England for a Newcomen engine-powered steamboat, but it was the improvement in steam engines by James Watt that made the concept feasible. William Henry of Lancaster, Pennsylvania, having learned of Watt's engine on a visit to England, made his own engine and in 1763 attempted to put it in a boat. The boat sank, and while he made an improved model he does not seem to have had much success, though he may have inspired others.

image:D'AbbansSteamshipModel.jpg In France, by 1774 Marquis Claude de Jouffroy and his colleagues had made a 13 metre (42 ft 8 in) working steamboat with rotating paddles, the Palmipède. The ship sailed on the Doubs in June and July 1776, apparently the first steamship to sail successfully. In 1783 a new paddle steamer, Pyroscaphe, successfully steamed up the river Saône for fifteen minutes before the engine failed, but bureaucracy thwarted further progress.

From 1784 James Rumsey built a pump-driven (water jet) boat and successfully steamed upstream on the Potomac river in 1786; the following year he obtained a patent from the State of Virginia. In Pennsylvania, John Fitch, an acquaintance of Henry, made a model paddle steamer in 1785, and subsequently developed propulsion by floats on a chain, obtained a patent in 1786, then built a steamboat which underwent a successful trial in 1787. In 1788, a steamboat built by John Fitch operated in regular commercial service along the Delaware river between Philadelphia PA and Burlington NJ, carrying as many as 30 passengers. This boat could typically make 7 to 8 miles per hour, and traveled more than during its short length of service. The Fitch steamboat was not a commercial success, as this travel route was adequately covered by relatively good wagon roads. The following year a second boat made 50 km (30 mile) excursions, and in 1790 a third boat ran a series of trials on the Delaware River before patent disputes dissuaded Fitch from continuing.