The Alexander cocktail is not to be confused with the "Brandy Alexander" which is made with Cognac.
The Alexander was first published in 1916 in Hugo Ensslin's "Recipes for Mixed Drinks" book. It is made with equal parts of gin, white crème de cacao and single cream.
Several versions exist on the origin of the Alexander. Its real origin therefore remains very uncertain, but it seems that the Alexander was created in New York before prohibition, in the 1910s, by bartender Troy Alexander. This white-colored cocktail is said to have been created for a dinner party celebrating Phoebe Snow, a railroad publicity character who always wore a white dress.