William was born on September 19, 1944, in Kenosha, Wisconsin, the son of William Kmack and Janina (Kromberg) Kmack.
He graduated from Bradford High School in 1963.
On May 24, 1969, William married Diane Gagnon at St Lucy Church in Racine, Wisconsin. The happy couple later moved to Bradenton, Florida, where William began a career in the tool and die industry and eventually founded his own business.
William was a proud member of the Hernando DeSoto Historical Society, where he served as Hernando from 2001-2002. He especially loved traveling with his wife, Diane, and enjoyed classic cars and attending car shows.
William is survived by his wife, Diane Kmack; nephews Daniel McAuliffe (wife: Kathryne) and Anthony McAuliffe (wife: Jennifer); and nieces Rebecca (Jon), Addy, Gracie, and nephew Scott.
He was preceded in death by his son, Christopher Alan Kmack, and his parents, William M. Kmack and Janina (Kromberg) Kmack.
