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
Kellogg Co. v. National Biscuit Co. a sample and commented that they were like "eating a whisk broom." Nevertheless, the cereal became successful, and Perky's company, the Shredded Wheat Company, continued to manufacture the product after he retired. The Kellogg Company started manufacturing shredded wheat cereal in 1912 after Perky's patents expired; after the Shredded Wheat Company objected, Kellogg stopped manufacturing their version in 1919. The nature of the settlement is not clear. In 1927, the Kellogg Company resumed manufacturing shredded wheat, prompting a lawsuit from the Shredded Wheat Company; the lawsuit was settled. In 1930, the Shredded Wheat Company was acquired by the National Biscuit