Bill Spencer began his career as a right-handed pitcher for Normandy High School. He went on to the University of Missouri, where he was impressive as a pitcher and right-handed hitter. Spencer pitched for the Hannum Painters to the District championship in 1938, and the following year pitched Keller Drug to the Muny League championship. He played for the Belleville Stags as a Semi Pro and subsequently signed with the Pittsburgh Pirates and pitched Class A ball at Hutchison, Kansas.

During World War II, Bill was a commander in the U.S. Navy of a mine sweeper. A damaged rotator cuff in his pitching shoulder caused him to move to the outfield and first base, where his all-around ability and powerful hitting was featured on outstanding clubs like The Mural Room, Shearer Chevrolet, Feld Chevrolet, and Barford Chevrolet. Spencer won the City Title in 1947.