National Tequila Day is observed on July 24 in the United States. The day celebrates the drink that has been there for centuries now. Tequila is distilled from a specific type of agave plant. Tequila has a long history with its origin that dates back to Mesoamerican times circa 1000 B.C., when indigenous Mexican tribes would harvest and ferment it. The modern-day tequila has gone through a lot of modifications to become the one that is available today.