Pinpointing the exact origins of root beer is difficult, as it seems to descend from a variety of other drinks including indigenous American medicinal beverages and European low-alcohol. However, root beer would not be commercialized or known by its familiar name until a 19th-century pharmacist got inspired by a cup of tea.

Pharmacist Charles Elmer Hires loved an herbal tea that he had sampled and worked with two college professors to turn the ingredients into a shelf-stable powder for commercial production. This dry tea could be transformed into something close to modern root beer, but consumers first had to mix it with water, sugar, and yeast to induce carbonation via fermentation.

This blend wasn't exactly convenient, so Hires' friend Russell Conwell suggested he make a liquid version to be mixed with soda water rather than make the consumer ferment it. Hires' original liquid recipe reportedly contained 25 different herbs, berries, and roots.

Hires originally planned to sell the beverage under the name "Hires' Root Tea," but he changed the name to "Root Beer” to better market to miners, per Conwell’s suggestion. Root beer was sold to the public at the 1876 Philadelphia Centennial Exhibition, and it proved extremely popular.