Sonic is known for its extensive menu featuring many flavored beverages, but one holds a special place in the restaurant's history — root beer. The restaurant was called Top Hat Drive-In when it began, but it was rebranded to Sonic in 1959, and root beer had an important role within the franchise long before it became what it is today.

Top Hat was originally a small drive-in root beer stand that accompanied a much larger restaurant called the Log House, which was Sonic founder Troy Smith's primary purchase. It operated as a counter-serve stand where customers had the option to eat at an outdoor table or in their car, much like Sonic today.