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
Joseph Kellogg became vice-president and director. Under Kellogg's supervision, this company built the steamboats "Governor Grover" and "Beaver". Soon later Kellogg sold out his interest in the Willamette Transportation Company and its boats, and formed a new transportation company with his brother, Jason, and his two sons. Kellogg then built the steamboats "Joseph Kellogg" and "Toledo" and placed his boats on the Columbia River, on the line to Washougal, Washington and the Cowlitz River. His two sons, Captains Orrin and Charles H., were put in command of these boats. The firm was incorporated as the Joseph Kellogg Transportation Company, and it became