Key Chain History
Key rings, like the jailer’s ring of keys, date back as far as the invention of the lock. Locks were handmade and very expensive. Because of this, there were very few of them. It wasn’t until Linus Yale invented the cylinder lock in 1848 and mass-produced inexpensive locks that keys were carried by the general population. One of the earliest souvenir keychains dates back to the 1893 World’s Fair in Chicago.