The Johnson Family is a concept popularized by William S. Burroughs and based on a similar concept found in Jack Black's book You Can't Win.
In short, a “Johnson” or “a member of the Johnson family” is someone who is dependable, helpful, and not a snitch. The word serves as a sort of badge of respect, or a shorthand way of vouching for a person’s character (e.g. “it’s okay; he’s a Johnson.”)
Burroughs, in My Own Business wrote that “a member of the Johnson family… wouldn't rush to the law if he smelled hop in the hall, doesn't care what fags in the back room are doing, stands by his word. Good man to do business with.”
In The Place of Dead Roads, Burroughs wrote:
A Johnson honors his obligations. His word is good and he is a good man to do business with. A Johnson minds his own business. He is not a snoopy, self-righteous, trouble-making person. A Johnson will give help when help is needed. He will not stand by while someone is drowning or trapped under a burning car.
And in an introduction to a new edition of Black’s book, Burroughs wrote:
A Johnson pays his debts and keeps his word. He minds his own business, but will give help when help is needed and is asked for. He does not hold out on his confederates or cheat his landlady. He is what they call in show business “good people.”