Penny Post

They set up a local post that used a uniform rate of one old penny for delivery of letters and packets weighing up to one pound within the cities of Westminster and London as well as in Southwark.

[3] Several deliveries took place a day within the city, and items were also delivered to addresses up to ten miles outside London for an extra charge of one penny.

On 10 January 1840, the Uniform Penny Post was established throughout Great Britain and Ireland, facilitating the safe, speedy and cheap conveyance of letters.

While the Post Office was initially skeptical, the new system proved to be a resounding success, leading to greater efficiency, speed, and profitability.

Davis' Penny Post operated in Baltimore, Maryland for several weeks of February 1856, leaving behind a handful of rare stamps.