Over just 50 years, Britain's railways grew from a handful of small lines carrying coal to the biggest industry in the strongest nation on the planet. A nation had built the railways and now those railways would build a nation, influencing working conditions for its employees, proving a valuable export across the globe and even changing warfare.Yet the story of railways up until the beginning of the Second World War concerned who they really belonged to - the private rail companies who were obsessed with profit, the public who rode them, or the government, who needed them at times of crisis but was reluctant to regulate.