William co-wrote the play The Happiest Years in 1949.
During World War II, William was part of Irving Berlin's "This Is the Army" touring show, which raised money for emergency relief.
In 1991, William was nominated for a Daytime Emmy Award in the category of "Outstanding Supporting Actor in a Drama Series" for his work on Guiding Light. The award eventually went to Bernard Barrow of Loving.
William's theater credits include:
- Our Town
- The Magnificent Yankee
- Romeo and Juliet
- Dear Charles
William's Guiding Light character, Henry Chamberlain, was originally supposed to be on the show for only fouir days. However, producers enjoyed the chemistry between William and Maeve Kinkead, who played his daughter Vanessa, so much that he stuck around for 15 years.