Frostie Root Beer is a brand of root beer sold in the United States of America.
 Frostie was originally produced in 1939 by The Frostie Beverage Company of Catonsville, Maryland, owned by George Rackensperger.
 At the end of 1979, the Frostie brand was sold to the Monarch Beverage Company of Atlanta, Georgia.
 After years of being under-promoted by Monarch in favor of Dad's Root Beer, the Frostie brand was sold in 2000 to Leading Edge Brands of Temple, Texas.
 In 2009, Leading Edge Brands sold the Frostie line of beverages to Intrastate Distributors Inc. of Detroit, Michigan.
MUG Root Beer, A PepsiCo Subsidiary/Root Beer Corporation is a brand name of root beer made by the New Century Beverage Company of San Francisco, California, a subsidiary of PepsiCo.
Virgil's Root Beer is a microbrewed gourmet root beer, developed by Edward Crowley and Jill Fraser Crowley, who was the company's president (and founded and serves as CEO of fashion brand Jill Milan).
 Virgil's Root Beer won the "Outstanding Beverage" Award at the International Fancy Food and Confection Show in 1994, 1996 and 1997.
 The quality of and demand for Virgil’s Root Beer prompted Whole Foods' request for a cola by the brand: “Whole Foods said, 'Give me a cola with Virgil’s, and you’re in.'”
Barq's is an American soft drink.
 Its brand of root beer is notable for having caffeine.
<ref name="http://www.overcaffeinated.org/database/soda-pop/barqs-root-beer.php">Caffeine Database | Caffeine and Ingredients in Barqs Rootbeer, OverCaffeinated.org's Report on the Ingredients in Barq's Rootbeer</ref> Barq's, created by Edward Barq and bottled since the turn of the 20th century, is owned by the Barq family but bottled by the Coca-Cola Company.
 It was known as Barq's Famous Olde Tyme Root Beer until 2012.
Ramblin' Root Beer is a root beer formerly made by The Coca-Cola Company.
 The product disappeared after Coca-Cola bought Barq's in 1995.
 A famous ad campaign for the product featured Sarah Jessica Parker.
 By the 1980s, it was available primarily only in fountain outlets.
A&W Root Beer is a root beer brand primarily available in the United States and Canada, started in 1919 by Roy W. Allen.
 In 1922, Allen partnered with Frank Wright.
 They combined their initials to create the brand "A&W" and inspired a restaurant chain, founded in 1922.
 Originally, A&W root beer drinks sold for five cents.
A&W Restaurants, Inc. is a chain of fast-food restaurants distinguished by its draft root beer and root beer floats.
 Its origins date back to when Roy W. Allen opened a walk-up root beer stand in Lodi, California, in 1919.
 Allen's employee Frank Wright partnered with him and founded the first A&W restaurant in Sacramento, California, in 1923.
 The company name was taken respectively from the initials of their last names—Allen and Wright.
 The company became famous in the United States for its "frosty mugs," where the mugs would be kept in the freezer and eventually get filled with A&W Root Beer before they are served to customers.
Root beer is a sweet North American soft drink traditionally made using the sassafras tree "Sassafras albidum" (sassafras) or the vine "Smilax ornata" (sarsaparilla) as the primary flavor.
 Root beer may be alcoholic or non-alcoholic, come naturally free of caffeine or have caffeine added, and carbonated or non-carbonated.
 It usually has a thick, foamy head when poured.
 Modern, commercially produced root beer is generally sweet, foamy, carbonated, nonalcoholic, and flavoured using artificial sassafras flavouring.
 Sassafras root is still used to flavor traditional root beer, but since sassafras was banned by the U.S. Food and Drug Administration due to the controversially claimed carcinogenicity of its constituent safrole, most commercial recipes do not contain sassafras.
 Some commercial root beers do use a safrole-free sassafras extract.
A&W Cream Soda is a cream soda carbonated soft drink introduced by A&W Root Beer in 1986.
 A&W Root Beer was first sold at a Veterans Day parade in Lodi, California in 1919 and the company established in 1922 by Frank Wright and Roy Allen.
 The first product they created was A & W Root Beer.
 It was not until 1986 that A&W Brands, headquartered in White Plains, N.Y. introduced A&W Cream Soda and A&W Diet Cream Soda through its network of franchised bottlers and distributors.
 Although cream soda had been created in 1852 by E.M. Sheldon, A&W Brands was one of the first American companies to make it commercially.
 In 1993, A&W Brands was purchased by Cadbury/Schweppes, and in 1995 Cadbury/Schweppes purchased the Dr. Pepper/Seven-Up Company, which made A&W a part of the Dr. Pepper/Seven Up, Inc.
 In 2001, DPSU purchased the Snapple Beverage Group (formally TriArc Beverages), and moved the New York-based company operations to its new headquarters in Plano, Texas.
 This acquisition put A&W within the same company as the top soda brand companies and made A&W Cream Soda the top brand in cream sodas.
The Monarch Beverage Company Inc is a diversified, international beverage company based in Atlanta, Georgia.
 The company's CEO is Jacques Bombal.
 The company was founded in 1965 by Frank Armstrong.
 Monarch Beverage Company aimed to establish itself by offering lesser-known soft drink brands that had strong regional sales and appeal.
 Monarch Beverage Company purchased Dad's from IC Industries of Chicago in 1986.
 Around that time, it was the second largest volume (12 million cases) root beer brand and was distributed by the Coca-Cola bottler network.
 In 2007, The Dad's Root Beer Company, LLC of Jasper, Indiana, acquired the Dad's Root Beer brand as well as the rights to Bubble Up, Dr. Wells and Sun Crest in the U.S. and some other countries from The Monarch Beverage Co. of Atlanta.

Question: What brand of caffeinated root beer took over popularity and ended Ramblin' Root Beer's popularity?
Answer: Barq's