Actor. He is best remembered for his role as the cranky but lovable grandfather, Walter Powell, on the television comedy series “Charles In Charge” from 1987 to 1990. Born in Grand Rapids, Michigan, Callahan began his acting career in the late 1950s. His other roles include the films, “The Walking Target” (1960), “Tropic Of Cancer” (1970), “Lady Sings The Blues” (1972), “Outlaw Blues” (1977), “The Burning Bed” (1984), “May Jean” (1994), “Extreme Honor” (2001), and his last work, “Born” (2007). His many television credits include, “ER”, “Dr. Kildare”, “The Governor & J.J.”, “The Golden Girls”, “Cybill”, “Caroline In The City”, and “Dennis The Menace.” He was also a successful stage actor. His acting career spanned for 47 years, and some 120 film and television roles. During the Korean War, he served with the USA Army in West Germany from 1951 to 1953. He died of cancer.