Moxie

Moxie is a brand of carbonated beverage that is among the first mass-produced soft drinks in the United States. It was created around 1876 by Augustin Thompson as a patent medicine called "Moxie Nerve Food" and was produced in Lowell, Massachusetts. The sweet soda is similar to root beer, but with a bitter aftertaste. It is flavored with gentian root extract, an extremely bitter substance commonly used in herbal medicine.

Source: Wikipedia