In 1913, the British Post Office realized that London’s congested traffic was slowing down mail delivery and something needed to be done about it. (They are turning in their graves if watching London’s traffic snarl these days.) That year, Parliament approved building the Post Office Railway, as it was officially known, and construction began two years later. The Great War intervened, however, and although the tunnels were nearly completed full operation began only in December of 1927.
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