US Mail Delivered Underground via Pneumatic Tubes (1893–1953)

Between 1893 and 1953, underground pneumatic tube systems for mail transport were utilized by the U.S. Post Office in various major cities. This idea gained popularity after Senator Ted Stevens referred to the internet as 'a series of tubes' in 2006. The initial implementations occurred in mid-19th century London, Paris, and Berlin, with Philadelphia being the first U.S. city to adopt the system in 1893 under Postmaster General John Wanamaker. The network grew to almost twenty miles of tunnels, and by 1898, cities like New York, Boston, Chicago, and St. Louis had established similar systems. Although the service paused during World War I and resumed in the 1920s, it ultimately ceased on December 12, 1953, due to the emergence of road delivery.