Root beer was created in the mid-1800s by Philadelphia pharmacistCharles Hires. The original root beer was a low-alcohol, naturallyeffervescent beverage made by fermenting a blend of sugar and yeastwith various roots, herbs and barks.
Today's commercial root beer is completely non-alcoholic andgenerally contains sugar, caramel coloring, a combination of artificialand natural flavorings, including some of those originally used, andcarbonated water for sparkle.
Source: The food lover's companion by S.T.Herbst.