Actor John Spencer was born John Speshock to a working-class family in Patterson, NJ, on December 20, 1946. He attended the Professional Children's High School in New York City, and while a student adopted the stage name John Spencer. Spencer began acting in his teens, and landed his first big break was he was cast as Henry Anderson on the TV series The Patty Duke Show. After the end of the show's run, Spencer resumed his education, enrolling at Fairleigh Dickinson University in Teaneck, NJ; he later transferred to New York University. In the early '70s, Spencer began pursuing a career as a stage actor in New York City, and in 1981, he won an Obie award for his performance in the play Still Life. In 1983, Spencer began working in film, appearing in supporting roles in two movies that year, War Games and Echoes. By the mid-'80s, Spencer was working steadily in movies and making frequent television guest shots; he was also earning increasing acclaim for his stage roles, receiving a Drama Desk Award nomination for his role in The Day Room in 1988.
However, Spencer's first real brush with fame came in 1990, when he won the role of Tommy Mullany, a tough but goodhearted lawyer, on the hit TV series L.A. Law. While Spencer's regular guy looks seemed to rule him out of leading man roles, his success on L.A. Law established him as a first-call character actor, and he began scoring higher-profile roles in a variety of higher-profile films (such as Presumed Innocent, Copland, Forget Paris, and The Rock), while earning higher billing in made-for-TV movies, and appearing in stage roles as his schedule permitted. In 1999, Spencer's career received yet another boost when he was cast as Chief of Staff Leo McGarry on the acclaimed television series The West Wing; Spencer's work as part of the ensemble cast earned him a Screen Actor's Guild award in 2001 and 2002, and he was nominated for an Emmy five times for Best Supporting Actor, winning in 2002. In the same year that his character Leo suffered a heart attack on West Wing, Spencer sadly suffered the same fate: after a severe attack, he died among friends and family in a Los Angeles hospital in December, 2005. He was 58 years old.