[1] He was the son of blue-collar parents Mildred (née Benzeroski), a waitress, and John Speshock Sr., a truck driver.

[6] 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.

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.

In 1986 he appeared on Broadway as Dan White, the killer of Harvey Milk, in Execution of Justice, alongside Stanley Tucci and Wesley Snipes.

Spencer was a supporting actor in the hit 1990 courtroom thriller Presumed Innocent, portraying a tough veteran homicide detective, starring opposite Harrison Ford.

[4] Many of Spencer's West Wing co-stars paid tribute to him at his funeral, including Martin Sheen, Dulé Hill, Joshua Malina, Janel Moloney, Richard Schiff, Alan Alda, Jimmy Smits, Aaron Sorkin, Allison Janney, James Mangold, David E. Kelley, and Bradley Whitford.

The show's writers decided to adapt Spencer's absence by saying that McGarry died of a heart attack on election night.