Contained in this series is the bulk of the material. It covers a myriad of business, educational, and charitable ventures. Developed within the series is the continuum of businesses started by Kellogg, comprising the Sanitas Nut Food Company, the Kellogg Food Company, and finally the Battle Creek Food Company. Additionally, it contains the records of the subsidiaries of the Battle Creek Food Company including Battle Creek College. The Battle Creek College records are notable because of the litigation involving the estate of Mrs. Mary F. Henderson, who left a large sum of money and land to the college to help prevent bankruptcy and closure of the school. The records of the farm land in Missouri are also valuable as a source for presenting the hardships of agricultural life during the depression through World War II. The final segment of the business papers contain the court records of Kellogg vs. Kellogg. They deal with the suit in which William sued John Harvey over the use of the family name in business.

The arrangement of subseries:

• Food Experiments -- 1898-1909, n.d.
• Copyright Papers - Kellogg -- 1876-1902
• Patent Papers -- 1886-1911, n.d.
• Sanitas Nut Food Company -- 1896-1908, n.d.
• Battle Creek Sanitarium
• Food Company -- 1903-1941, n.d.
• Kellogg Toasted Rice Flake Company -- 1907-1910
• Kellogg Toasted Corn Flake Company -- 1907-1940
• Colax Comany -- 1907-1908
• Yogurt Company -- 1907-1908
• Battle Creek Cereal Coffee Company -- 1906-1921, n.d.
• Kellogg Food Company -- 1908-1919, n.d.
• Battle Creek Food Company, 1917-1950 Subsidiaries -- 1898-1946
• Henderson Estate -- 1924-1959
• Kellogg vs. Kellogg Volumes. [1896-1948] -- 1907-1922, n.d.