James MacArthur was the adopted son of the famous playwright Charles MacArthur and stage and screen starlet Helen Hayes. Following in his parents' footsteps, McArthur pursued a career in the arts, acting for radio, theater, television, and film. MacArthur starred in several Disney films of the 1950s and '60s, including "Third Man on the Mountain," "Kidnapped," and "Swiss Family Robinson." He had guest roles in many television episodes of popular series such as "Gunsmoke" and "The Alfred Hitchcock Hour," and he played a preacher in the Clint Eastwood western "High 'Em High."
It was thanks to "High 'Em High" writer Leonard Freeman — also an executive producer of "Hawaii Five-O" — that MacArthur was cast as Danny "Danno" Williams. Although MacArthur played the role for 11 years, he left before the show's final season out of boredom, feeling that the series had become too predictable. He went on to guest-star in numerous television shows throughout the 1980s, although his career would slow down significantly in '90s. Like his co-star Kam Fong, MacArthur briefly reprised his role as Danny Williams in the 1997 "Hawaii Five-O" TV movie.
While MacArthur was in talks to make a cameo appearance in the pilot episode of "Hawaii Five-0" in 2010 (via Digital Spy), it did not come to pass. MacArthur died of natural causes in Jacksonville, Florida, in October 2010, at the age of 72.
