The first steam locomotive built in the United States was Tom Thumb.
Designed and built by inventor Peter Cooper in 1829, Tom Thumb was created for the Baltimore and Ohio Railroad. Its compact vertical boiler and unusual construction were intended to demonstrate that steam power could handle the railroad’s sharp curves and modest track.
Tom Thumb was not designed for regular revenue service, but its 1830 demonstration convinced B&O directors to pursue steam locomotion. During a famous trial near Baltimore, it raced a horse-drawn rail car. Tom Thumb initially pulled ahead, but a slipped blower belt caused it to lose steam, allowing the horse to win.
The locomotive is sometimes confused with the Stourbridge Lion and John Bull, but both were built in Britain and imported to the United States. The DeWitt Clinton was also an early American locomotive, but it was built later, in 1831. Tom Thumb’s importance lies in being the first American-built locomotive to operate on a common-carrier railroad.