Who is Walter Starbuck from Jailbird and what is their importance?

Starbuck is the novel's central character, and its narrator. He is a white male American, in his eighties at the time the novel takes place, born to a pair of Polish immigrants who changed their name from Stankiewicz during an early phase of their lives in America, and who worked as house servants for a reclusive industrialist, Alexander Hamilton McCone. The novel narrates how Starbuck grows up as McCone's protégé, living his life as a young adult according to his (McCone's) very strict, and arbitrary, rules.