Once Trevithick had built the first locomotive back in 1804, the country realised that steam could do a lot more than just be used on a static engine. After this initial leap, a duo of William Hedley and Timothy Hackworth built a locomotive, Puffing Billy, which utilised a crank shaft to join the wheels together - which provided both a smoother ride and also better traction. George Stephenson the improved on this design yet further, and created "Stephensen's Rocket".
Stephensen's development then paved the way for the Stockton & Darlington railway to appoint him Engineer; where he gained permisson to use steam powered locomotives on the route. This line became the first public locomotive hauled railway in the world.
Due to the nature of the railway in its early stages, the network grew up as a patchwork of local railways serving local needs. Small private companies operated short lines. As demand increased, more and more lines were added, and by the mid-1800's, the majority of the country had some form of rail connection.
With this expansion came the need for regulation. The 1840 Act, "Regulating Railways", paved the way for Railway Inspectors to examine and determine the cause of accidents, providing recommendations on how to prevent future incidents. This led to standards of construction being mandated.
During the First World War the entire network was brought under state control. This led directly to the formation of 'The Big Four'.
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