former mail service in the Western United States
via Wikipedia infobox
Pony Express advertisement Pony Express postmark, 1860, westbound
The Pony Express was an American express mail service that used relays of horse-mounted riders between Missouri and California. It was operated by the Central Overland California and Pikes Peak Express Company.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).