Daisies are essentially a style of sour drink that's sweetened with a liqueur and/or flavored syrup, and topped with sparkling water. However, the drink's been around for 150 years and the template has evolved, so there's more to understanding the Daisy. The Daisy cocktail, a classic sour with added orange liqueur and soda water, has a history rooted in the late 19th century and is considered a precursor to many modern cocktails. Its origins are often traced back to the late 1800s in Washington, D.C., with variations appearing in early cocktail books like Jerry Thomas's The Bartender's Guide. The Daisy's simple formula of base spirit, orange liqueur, citrus, and soda water has served as a template for numerous cocktails, including the Margarita and the Sidecar.