William Joseph McGuire Jr., affectionately known as "Biff" during his high school football days, initially pursued a degree in agricultural engineering at the University of Massachusetts. However, after realizing that farming wasn't his calling, he left academia and enlisted in the U.S. Army, where he was stationed in Oxfordshire during the final stages of World War II.
While attending the Defence Academy of the United Kingdom at Shrivenham, McGuire developed an interest in the performing arts, which led him to be assigned as a set painter. His artistic endeavors caught the attention of a local drama critic, who encouraged him to audition for a role in William Saroyan's play The Best Years of Our Lives. McGuire's successful audition led to his move to London, where he eventually made his way to Broadway.
On the Great White Way, McGuire appeared in numerous productions, including the original 1949 production of South Pacific. He went on to star in several other notable productions, including Finian's Rainbow in 1960, which co-starred his wife, the English actress Jeannie Carson. The couple continued to perform together in off-Broadway plays, such as Mary, Mary, Camelot, and Cactus Flower, and were long-standing members of the Seattle Repertory Theatre.
McGuire's transition to television acting began in the early 1950s, and he went on to pen several episodic screenplays and sell an original drama to the BBC. He made sporadic appearances in film, including roles in The Phenix City Story, The Thomas Crown Affair, and The Heart Is a Lonely Hunter. On television, he starred in several episodes of Alfred Hitchcock Presents and played one of the three principal characters in the nostalgic newspaper drama series Gibbsville, alongside Gig Young and John Savage.
Before his retirement from acting in 2013, McGuire made recurring appearances on the soap operas Search for Tomorrow and Santa Barbara.
