Answer: The Prohibition

Cocktails seem like an ubiquitous and eternal element of the alcohol drinking experience, but they weren’t always a staple of bars and dinner parties across America. Although the precise origin of the cocktail is unknown (there is no recorded moment in time where somebody decided that fruit juice, bitters, and liquor were perfect companions), the first examples of cocktails appeared in the early 19th century. Still the concept didn’t gain widespread appeal and even through the Civil War cocktails weren’t particularly popular (there wasn’t even a formal recipe book or guide to creating them published until 1862).

What really put cocktails on the map was, ironically, the Prohibition. When the U.S. government banned alcohol, drinking didn’t go away, it just went underground. In the process, the quality of alcohol available to U.S. drinkers plummeted as the majority of alcohol production within the U.S. became the province of moonshiners and the proverbial bathtub-gin makers. The joke about bathtub gin is well founded, however, as gin was a very popular form of alcohol since it didn’t require the advanced maturation that other alcohols, like bourbon, required.

Quickly created gin tastes foul and the patrons of underground drinking establishments, known as speakeasies, were quick to mix their bottom-shelf quality gin with juice, syrups, bitters, and other adornments to take the stinging edge off. The inclusion of fruit juices and the like also had another advantage: not only did it mask the poor taste of the gin, but it made it easy to gulp down your drink if the speakeasy was raided while you were in the middle of an evening drink.

When the Prohibition ended, the American people might have gained access to higher quality booze again, but they never lost their taste for mixing it in cocktails of all flavors.