City and South London Railway

The City and South London Railway was the first successful deep-level underground tube railway in the world and the first major railway anywhere to run on electric traction. Construction began in 1886 and the line opened to the public on 18 December 1890, at first running 3.2 miles between the City of London and Stockwell before growing to 13.5 miles and twenty-two stations between Camden Town and Morden. It proved two things at once: that a tunneling shield could bore a deep tube railway under a city without buying up expensive surface land, and that electric traction, adopted only after the planned cable-hauled systems contractor went bankrupt, could run a major railway in practice, and both lessons shaped every underground railway built after it.