Who is Cooper Family from Travels with Charley: In Search of America and what is their importance?

Steinbeck grows up with the Cooper children, a Black family consisting of a hard-working father, an immaculate housekeeping mother, a son of Steinbeck's age and two other sons, one a year older and one a year younger. Steinbeck's only experience with Black people while growing up consists of his interactions with the Cooper family.