I've been reading Maureen Ogle's book, Ambitious Brew, which is a history of beer in America. It is a great book, full of interesting stories about Pabst, Busch, Schlitz and others.
One of the most fascinating discussion relates to how we Americans came to think of substituting rice and corn (or "adjuncts" as they were called in the brewing industry) for barley in beer.
There is a common mantra that the main selling beers in the US (Bud, Miller, Coors) are "low quality", and that drinking them is akin to drinking "horse piss." Ogle shows that this perspective - particularly the perspective the adjuncts are low quality - rose out of the "pure food movement" in late 19th century, and is as much a result of sensationalist journalism than anything else.
Ogle writes that the "The [prohibitionist] crusaders also used the "pure food" crazy as a means of attacking brewers." There were people like George Angell, who wrote Jungle-like reports on the nation's food supply and stirred up (much unsubstantiated) concern about glucose, a sweetener made from corn. Realizing that some brewers used corn (and thus somehow must use glucose) provided the "in" that many prohibitionists needed to sell sensationalized stories to the media.