By the end of the 18th century the steam engine was well established in mines and factories, but not yet as a means of locomotion. Early "wagonways" hauled coal from pits to ports by horse; Richard Trevithick's 1804 locomotive and the Stockton and Darlington Railway of 1825 proved the concept but were not designed for heavy passenger traffic. The need to link the port of Liverpool with the textile mills of Manchester — for which the canals were overstretched and expensive — gave rise to the first true railway project.

Once its engineer George Stephenson committed the line to steam haulage, the question of which engine to use was settled at the Rainhill Trials of October 1829. Among five contenders, the Rocket — designed with his son Robert, featuring a multi-tubular boiler, a separate firebox, and a blastpipe — reached around 47 km/h and won; every essential principle of the modern locomotive was already there. On the opening day of 15 September 1830, the Prime Minister, the Duke of Wellington, and thousands of spectators were present, but the day was also marked by the first great railway accident: the MP William Huskisson was struck and killed by a locomotive. Even so, within six months the line was carrying thousands of passengers a day.

The model spread quickly. By the 1840s Britain had thousands of kilometres of track; in 1869 the first US transcontinental line was joined at Promontory Summit; in 1903 the Trans-Siberian reached Vladivostok; from 1888 the Berlin–Baghdad project was being planned — railways created, for the first time, a genuine internal market across whole continents. Farm produce reached cities, coal reached factories, soldiers reached fronts, and mail reached postal centres within hours; standard time zones (Greenwich railway time in 1847, US time zones in 1883) were invented because of train schedules.

The historian Eric Hobsbawm called this period the "railway age": the industry, capital accumulation, and urbanisation of the mid-19th century moved largely to the rhythm at which tracks were being laid. The railway was not just a means of transport but the first great technical system to shrink space and standardise time; today's global logistics network, suburban city, and habit of "living by the timetable" are direct links in a chain that began at Liverpool and Manchester.