Gibson
The Gibson was invented by Walter D K Gibson in San Fransisco in the late 1800's, sometime around 1898 at the Bohemian Club in San Francisco. Here is Charles Pollok Gibson's account (Walter D K Gibson is Charles' father's great uncle) of his family's cocktail history in his own words...
"The story goes that WDK Gibson objected to the way the bartender at the Bohemian made martinis. He preferred them stirred, and made with Plymouth Gin. He also believed that eating onions would prevent colds. Hence the onion. In his version, a twist of orange was held over the glass so that a bit of the oil would fall on the top. The original Gibson--as with all martinis--was also sweeter before the first world war [with sweet vermouth], with about a 1/4 vermouth. . .He used to drink them until he died in 38; and during prohibition his wife, whose sister was Lillie Spreckels, insisted that the gin be prepared specially at home lest an inferior quality slip in. Alas I have no idea what her recipe was."
2 1/2 oz gin
1/2 oz dry vermouth
1 or 3 cocktail onions for garnish
Pour the ingredients into a mixing glass with ice cubes. Stir well.* Strain into a chilled cocktail glass. Garnish with the cocktail onion.
The onion garnish also marries well with vodka when it replaces the gin for a Vodka Martini.
*Water is added to the drink from the ice that is used to mix it with. The role of the water in any cocktail is to calm down the flavors all around and to reduce the "burn" of the alcohol. This is extremely important for creating a cocktail that is smooth and relaxing.