William M. Griswold was the last child of Amos Griswold and his first wife Martha ('''' Munson). William's older brother, George Griswold, was his business partner for several years. Their younger half-brother, Eugene S. Griswold, came to live and work with them in Columbus, Wisconsin, in the 1850s. William Griswold married Mary Sofied of
Yates County, New York, in July 1868. They had two children, William and Mary. Griswold died of cancer at his home in Columbus at the age of 66. ==Electoral history==