If the telegraph was the Victorian internet, then the modern, government-run, pre-paid postal system (which didn’t come together much earlier) was the modern DARPA, or something.
The Penny Black was the world’s first adhesive postage stamp of a public postal system. It was issued by the United Kingdom of Great Britain and Ireland on 1 May 1840, for use from 6 May of that year. Although all London post offices received official issues of the new stamps, other offices throughout the United Kingdom did not, instead continuing to accept postage payments in cash only for a period. Post offices in some localities, such as those in the city of Bath, began offering the stamp unofficially after 2 May.
Thomas Moore Musgrave was postmaster of Bath from 1833 until his death in 1854. He was the first person in the world ever to send a stamp. The famous May 2nd Penny Black, was posted from Bath on a letter a few days before stamps were officially allowed.