Constructed by the Underground Electric Railways Company of London, between Baker Street and Lambeth North, (then called Kennington Road). It was later extended to Elephant & Castle, and then to Watford and Stanmore. The contraction to "Bakerloo" rapidly caught on, and the official name was changed to match it in July 1906. Owing to falling customer usage, it was eventually taken into public ownership, and became part of the London Underground system.
Credit for this entry to: Alan Patient of www.plaquesoflondon.co.uk