The first practical locomotive was constructed in England in 1804 by the British engineer and inventor Richard Trevithick. This locomotive, with four driving wheels, had smooth wheels operating on smooth metal rails; its success proved that sufficient traction could be obtained without using gear wheels and a cogged or toothed track. Equally important, the Trevithick locomotive exhausted its steam into the smokestack of the engine's firebox; this provided a forced draft for the fire in the firebox and was employed on all subsequent steam locomotives.
George Stephenson, a self-taught British inventor and engineer, designed the Rocket, an early steam locomotive. In 1829 the Rocket demonstrated that steam locomotion was possible.
After the successful trials of the Trevithick locomotive, a number of moderately successful locomotives were built in England, primarily for use in mining. Not until 1829 was a locomotive developed for use in a railway carrying both passengers and freight. In that year the Rocket, a locomotive designed by the British engineer George Stephenson, won a competition sponsored by the Liverpool and Manchester Railroad. The Rocket pulled a load of three times its own weight at the rate of 20 km/h (12.5 mph) and hauled a coach filled with passengers at 39 km/h (24 mph). This performance stimulated the building of other locomotives and the extension of railroad lines.
Also in 1829, the first locomotive to operate in the western hemisphere was given a trial at Honesdale, Pennsylvania. This locomotive, the Stourbridge Lion, had been built in England for the Delaware and Hudson Canal Company. In the following year, the first locomotives built in the U.S. were put into operation: The Best Friend was operated by the South Carolina Canal and Railroad Company, and the Peter Cooper, also known as the Tom Thumb, was operated by the Baltimore and Ohio Railroad Company. The Peter Cooper was little more than an enlarged model, but it outperformed the Rocket. Old Ironsides, built by the American industrialist Matthias William Baldwin for the Philadelphia, Germantown and Norristown Railroad Company, was a four-wheeled locomotive weighing about 5 metric tons. It was given its first road tests in 1832 and put into service almost immediately.
Many mechanical improvements were subsequently made, both in England and in the U.S. These two countries have generally paralleled each other in locomotive development. In 1831 the swiveling locomotive truck, now commonly called a bogie, carrying a set of supporting wheels supplanted the fixed bogie; in 1836 the outside coupling of pairs of driving wheels was introduced; and in 1837 counterbalances were applied to driving wheels and other parts to smooth the operation of the engine. The first locomotive with six driving wheels and a four-wheeled leading bogie, often called a ten-wheeler, appeared in 1847. In 1863 the Mogul type locomotive, with six driving wheels and a two-wheel leading bogie, came into use; and in 1867 the first Consolidation type locomotive with eight coupled drivers and a two-wheeled leading bogie was built. These heavy-hauling types supplemented the standard, so-called American type locomotive in use for the previous quarter century. The American type, equipped with four driving wheels and a four-wheel leading bogie, was excellent for ordinary service but was not adapted to pulling long and heavy freight trains over severe grades.