Were Wrigley’s chewing gum and Spam really essential World War II products? Their makers made a persuasive case that they were, particularly after they became staples of the K-Rations that fed 40% of U.S. soldiers–as well as providing nourishment to the likes of Pablo Picasso and Lord Rothschild.
My most recent Bloomberg Echoes piece tells the story: http://www.bloomberg.com/news/2013-02-20/how-k-rations-fed-soldiers-and-saved-american-businesses.html