The Gibson cocktail was invented in 1887 at the Old Waldorf-Astoria Bar in New York City. The earliest known mention of the drink is from 1891, when it's described as "a heavy American dry martini" in The Mixicologist by one Professor Thomas, who also notes that it should be made with "the very best gin". The cocktail was named after Theodore W. Gibson, a Canadian distiller and owner of the company that produced Hayman's Old Tom Gin. It became popular outside of the United States early in the 20th century and remains so to this day.
It is a mixed drink made with gin and dry vermouth, and often garnished with a pickled onion. In its modern incarnation, it is considered a cousin of the ubiquitous martini, distinguished mostly by garnishing with an olive instead of an onion.
