There are many stories associated with the margarita's origins. The prevailing one credits Texas socialite Margaret Sames, who combined the ingredients in salt-rimmed glasses with the Spanish version of her name etched on them.
Moisten half of the outer rim of a chilled coupe with the lime wedge and coat lightly with salt. Fill a cocktail shaker with ice. Add the tequila, Cointreau and lime juice and shake well. Strain the drink into the prepared glass.