The railway system of Great Britain started with the building of local isolated wooden wagonways starting in the 1560s. A patchwork of local rail links operated by small private railway companies developed in the late 18th century. These isolated links expanded during the railway boom of the 1840s into a national network, although initially being run by over one hundred competing companies. Over the course of the 19th and early 20th centuries, many of these were amalgamated or were bought by competitors until only a handful of larger companies remained. The period also saw a steady increase in government involvement, especially in safety matters, such as the Railway Inspectorate.

Railway Mania was a stock market bubble in the rail transportation industry of the United Kingdom of Great Britain and Ireland in the 1840s. It followed a common pattern: as the price of railway shares increased, speculators invested more money, which further increased the price of railway shares, until the share price collapsed. The mania reached its zenith in 1846, when 263 Acts of Parliament for setting up new railway companies were passed, with the proposed routes totalling 9,500 miles (15,300 km). About a third of the railways authorised were never built—the companies either collapsed due to poor financial planning, were bought out by larger competitors before they could build their line, or turned out to be fraudulent enterprises to channel investors' money into other businesses.