A Moscow mule is a cocktail made with vodka, ginger beer and lime juice, garnished with a slice or wedge of lime. The drink is a type of buck and is sometimes called a vodka buck.
George Sinclair's 2007 article on the origin of the drink quotes the New York Herald Tribune from 1948:
The mule was born in Manhattan but "stalled" on the West Coast for the duration. The birthplace of "Little Moscow" was in New York's Chatham Hotel. That was back in 1941 when the first carload of Jack Morgan's Cock 'n' Bull ginger beer was railing over the plains to give New Yorkers a happy surprise…The Violette Family helped. Three friends were in the Chatham bar, one John A. Morgan, known as Jack, president of Cock 'n' Bull Products and owner of the Hollywood Cock 'n' Bull Restaurant; one was John G. Martin, president of G.F. Heublein Brothers Inc. of Hartford, Conn., and the third was Rudolph Kunett, president of the Pierre Smirnoff, Heublein's vodka division. As Jack Morgan tells it, "We three were quaffing a slug, nibbling an hors d'oeuvre and shoving toward inventive genius". Martin and Kunett had their minds on their vodka and wondered what would happen if a two-ounce shot joined with Morgan's ginger beer and the squeeze of a lemon. Ice was ordered, lemons procured, mugs ushered in and the concoction put together. Cups were raised, the men counted five and down went the first taste. It was good. It lifted the spirit to adventure. Four or five days later the mixture was christened the Moscow mule...
Mayo Methot's husband, Percy T. Morgan,an oil tycoon, was a co-owner of the Cock n' Bull restaurant.
This story was well known for years, however in 2007, a new version of the invention of the Moscow mule cocktail was published. In this story the cocktail's inventor was Wes Price, getting the idea from Hudes Potache, Morgan's head bartender and the drink was born out of a need to clear the bar's cellar, packed with unsold inventory, including vodka and ginger beer.
Eric Felten quotes Wes Price in an article that was published in 2007 in The Wall Street Journal
"I just wanted to clean out the basement," Price would say of creating the Moscow mule. "I was trying to get rid of a lot of dead stock." The first one he mixed he served to the actor Broderick Crawford. "It caught on like wildfire," Price bragged."
1 ½ oz QURI Vodka
3 oz Ginger Beer
½ oz Juice of Half a Lime\1Lime Wedge1Slice of Ginger
1 Lime Wedge
1 Slice of Ginger
Few Mint Leaves