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
Clark Kellogg score 51 points and grab 24 rebounds. His 51-point game is still an Ohio high school state finals record. Kellogg also played in the McDonald's All-American and Capital Classic games. From 1979 to 1982, Kellogg played for Ohio State University, where he earned All-Big Ten Conference and Most Valuable Player honors; in 1996, he received his marketing degree. In June 2010, Ohio Gov. Ted Strickland appointed Kellogg to the university's board of trustees, where he sits today. In 1982, Kellogg declared for the NBA draft after his junior year of college and was the 1st round draft pick of the