Breakfast cereal he launched the Cornflakes brand, which overnight captured a national market. Soon there were forty rival manufacturers in the Battle Creek area. His brother William K. Kellogg (1860–1951) worked for him for many years until, in 1906, he broke away, bought the rights to Cornflakes, and set up the Kellogg Toasted Corn Flake Company. William Kellogg discarded the health food concept, opting for heavy advertising and commercial taste appeal. Later, his signature on every package became the company trademark. The second major innovator in the cereal industry was Charles W. Post, a salesman who was admitted to Kellogg's sanitarium as
Operation Cornflakes stamps used on the envelopes were forged 6 pf and 12 pf Hitler-head stamps intended to look identical to genuine German stamps of the era, though these forgeries were printed by the Office of Strategic Services (OSS). Operation Cornflakes Operation Cornflakes (1944–1945) was a World War II Office of Strategic Services (OSS) Morale Operation (MO). Operation Cornflakes involved tricking the German postal service, Deutsche Reichspost, into inadvertently delivering anti-Nazi propaganda to German citizens through mail. The operation involved special planes that were instructed to airdrop bags of false, but properly addressed, mail in the vicinity of bombed mail trains. When