From 1999 through 2005, John Spencer was most recognized for his role as Chief of Staff Leo McGarry on The West Wing.

While Martin Sheen, Rob Lowe, Dulé Hill, Allison Janney, Janel Moloney, Richard Schiff, and Bradley Whitford will all reprise their roles for the reunion special, Sterling K. Brown will read the part of Leo McGarry, the White House Chief of Staff. In 2005, John Spencer, who played Leo in the program, passed away.

Spencer also played President Bartlet’s best friend and a father figure to White House Deputy Chief of Staff Josh Lyman (Bradley Whitford). He also served as the President’s top advisor and vice-candidate for Matt Santos’ presidential campaign throughout the series.

Spencer died of a heart attack on December 18, 2005, four days before his 59th birthday, at the Olympia Medical Center in Los Angeles, according to his spokesperson.

He had recorded two episodes of The West Wing that were in post-production at the time – « Running Mates », in which Leo struggles during the debate preparation, and « The Cold ». John’s death was written into the series for the episodes « Election Day Part I » and « Election Day Part II ». His character also passed away.

In Part I, Leo retires to his hotel room for a nap before the election results are announced. When Annabeth Schott (Kristin Chenoweth) attempts to wake him up, she discovers that he has passed out. As the election results start to roll in, he is transported to the hospital. Josh Lyman travels to the hospital to see Leo in Part II, only to find out that he has died. Through phone calls and chats, the rest of the core characters learn of this. Santos (Jimmy Smits) wins the election.

Three of the pallbearers during Leo’s funeral are President Bartlet (Martin Sheen), President-elect Santos, and Josh Lyman. Leo was laid to rest in Arlington National Cemetery. In real life, Kristin Chenoweth sang “For Good” from Wicked during John’s private burial. In his hometown of Totowa, NJ, he was laid to rest in Laurel Grove Memorial Park.

Spencer was born John Speshock Jr. and grew up in Totowa, New Jersey, according to his obituary. He moved away from home when he was 16 to attend the Professional Children’s School in New York City, and won a recurring part on The Patty Duke Show in 1963. He went on to have minor roles in films and on television until he had a breakthrough performance alongside Harrison Ford in the 1990 picture Presumed Innocent. That led to a recurring part on L.A. Law, which drew the attention of West Wing creator Aaron Sorkin.

When Spencer died, Sorkin told the New York Times that when he was casting The West Wing, he told the casting director, “We need someone like John Spencer,” to which the casting director replied, “We will never get John Spencer.” However, he agreed, and the rest is history.

John’s departure was felt keenly by his peers and many viewers for the rest of the series. Leo McGarry was mourned on the program by the many individuals who admired him on both sides of the aisle, just as John was in real life. C.J. Cregg (Allison Janney) says that she never ceased thinking of the chief of staff office as Leo’s office while handing it over to the incoming Josh Lyman. She then offers him a letter that reads, “WWLD?” (What Would Leo Do?).

Spencer was nominated for one Golden Globe and five Emmy Awards for his performance on The West Wing, winning Outstanding Supporting Actor in a Drama Series in 2002.