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
John Harvey Kellogg Kellogg, his younger brother Will Keith Kellogg, and other family members. There is considerable disagreement over who was involved in the discovery, and the role they played. According to some accounts, Ella suggested rolling out the dough into thin sheets, and John developed a set of rollers for the purpose. According to others, John had the idea in a dream, and used equipment in his wife's kitchen to do the rolling. It is generally agreed that upon being called out one night, John Kellogg left a batch of wheat-berry dough behind. Rather than throwing it out the next morning, he