John Collins was a head waiter at Limmer’s Hotel (London, around 1807), who created his own version of Gin Punch with cold soda water. His punch version made him famous: his clientele included admirals and baronets, dukes and generals, who spread the drink around the world.
By the start of the 1870's, it had caught on in American saloons, although at first it was usually made with a Dutch gin (jenever), rather than the Old Tom gin that Mr. Collins used. It soon became a cult summer drink. Around the 1950's in America, it was difficult to find jenever: the Americans started to use whisky in the Collins' drinks instead. This is not such a strange choice, given the fact that jenever has some whisky-ish traits. However, the gin version is making a comeback in The United States.
Nowadays, the drink with Old Tom gin is called Tom Collins; the name John Collins is reserved for the variety with Dutch gin (jenever). Did this history lesson make you thirsty for Collins drinks? Be welcome at The Court!