Kellogg was born on April 7, 1860 in Battle Creek, Michigan. He was married to Ella Osborn Davis from 1880 until her death in 1912. They had five children. Then he was married to Carrie Staines from 1918 until her death in 1948. Kellogg died on October 6, 1951 in Battle Creek, Michigan from heart failure, aged 91.
↑"W.K. Kellogg, 91, Dead in Michigan. Breakfast Food Manufacturer Set Up Multi-Million Dollar Welfare Foundation in '30". Associated Press in New York Times. October 7, 1951, Sunday. "Will Keith Kellogg, founder of the breakfast cereal company that bears his name, died here today in Leila Hospital. The pioneer cereal manufacturer, known to millions by his breakfast food trade mark initials — W.K. — succumbed at the age of 91 after a long circulatory illness."