Spencer was born John Speshock, Junior. in New York City, and was raised in Totowa, New Jersey. He was the son of blue-collar parents Mildred (née Benzeroski), a waitress, and John Speshock Senior, a truck driver. Spencer"s father was of Irish and Czechoslovakian descent, while his mother was of Ukrainian and Rusyn ancestry.
He attended Fairleigh Dickinson University, but did not complete a degree.
With his enrollment at the Professional Children"s School in Manhattan in 1963, Spencer found himself sharing classes with such fellow students as Liza Minnelli and violinist Pinchas Zukerman. Spencer often referred to himself as a "dyed-in-the-wool liberal" and described Franklin Delano Roosevelt as one of his heroes. Spencer began his television career on The Patty Duke Show, and eventually began appearing in supporting roles in feature films commencing with 1983"s WarGames.
The same year, Spencer joined the cast of the television series Los Angeles Law, playing rumpled, pugnacious, street-wise trial attorney Tommy Mullaney.
Spencer"s work also extended to video games, portraying the role of Captain Hugh Paulsen in the 1995 video game Wing Commander IV: The Price of Freedom. McGarry was later a senior staff consultant to President Josiah Bartlet and a vice presidential candidate until his death in 2005.
Both Spencer and McGarry were recovering alcoholics. Spencer died of a heart attack in a Los Angeles hospital on December 16, 2005, four days before his 59th birthday.
At Spencer"s private funeral, his West Wing castmate, Kristin Chenoweth, sang the musical number "Foreign Good" from the Broadway musical Wicked.
Spencer"s remains were interred at Laurel Grove Memorial Park in his hometown of Totowa. At the time of his death, Spencer had filmed two of the five West Wing episodes that were in post-production: "Running Mates" and "The Cold". Spencer"s death was subsequently written into the show"s seventh and final season, in which McGarry was said to have died of a heart attack on election night.
Spencer"s name remained in the opening credits throughout the remainder of the show"s season.
A tribute to Spencer, read by the show"s lead Martin Sheen, was delivered before one of the final episodes of the series.
He won an Emmy Award in 2002 for his role as White House Chief of Staff Leo McGarry on the National Broadcasting Company political drama series The West Wing. He won an Obie Award for the 1981 off Broadway production of Still Life, about a Vietnam War veteran, and received a Drama Desk nomination for "The Day Room." He became a full-fledged supporting actor with the hit 1990 courtroom thriller Presumed Innocent portraying a tough, veteran homicide detective, starring opposite Harrison Ford. In 1999, Spencer was cast as White House Chief of Staff Leo McGarry on the hit National Broadcasting Company political drama series The West Wing. Spencer"s role on the show eventually earned him a Primetime Emmy Award for Outstanding Supporting Actor in a Drama Series in 2002, after being judged on the show"s third season episodes "Bartlet for America" and "We Killed Yamamoto".
