Vodka, ginger beer, and fresh lime in a copper mug — the 1940s marketing exercise that became a classic.
The Moscow Mule was created in 1941 at the Cock 'n' Bull pub in Hollywood through a three-way collaboration: John G. Martin (who had recently bought the Smirnoff vodka brand and was struggling to sell it), Jack Morgan (who owned the Cock 'n' Bull and had an excess of ginger beer), and a woman with a new business making copper mugs. All three had surplus stock; together they created an icon.
The copper mug is both functional and marketing. Copper conducts temperature extremely well, keeping the drink colder for longer than a glass would. It also adds a faint metallic sharpness that amplifies the ginger. The Moscow Mule made vodka acceptable to American drinkers who associated it with communist Russia — by 1950, Smirnoff was the best-selling spirit in the US.
Replace vodka with bourbon. Many experienced drinkers prefer this version. The bourbon's caramel and spice is a better partner for ginger than neutral vodka.
Replace vodka with blanco tequila. The agave and ginger combination is unexpectedly good.
Replace vodka with Gosling's Black Seal dark rum. This is technically a different named cocktail, but the technique is identical.