I think "Jack" is supposed to be a nickname for "Jackson."
>>I think “Jack” is supposed to be a nickname for “Jackson.”
Phil Harris was one of his sidekicks.
From Wikipedia:
Phil Harris as himself - A skirt-chasing, arrogant, hip-talking bandleader, he constantly put Jack down (in a mostly friendly way). He referred to Mary as “Livvy” or “Liv”, and Jack as “Jackson”. Harris explained this once by saying it’s “as close as I can get to jackass and still be polite”
Jack Benny’s first name was not Jackson, his real name was Benjamin Kubelsky.