Spokeswoman Jaime Larkin says the 89-year-old died Monday at the fund's hospital in Los Angeles. Larkin says the actor died of natural causes after being hospitalized with pneumonia.
The character actor appeared in a wide range of TV shows, from "Perry Mason" in the 1950s to Kelsey Grammer's "Boss" in 2011.
The Illinois native, is survived by his wife of 65 years, actress Barbara Collentine.
Funeral plans were not immediately announced.