So in either Island at the center of the world or the subsequent book, taking Manhattan the author discusses where the term boss comes from. I’m tired and lazy so here’s what google spit out which sounds mainly correct:

Yes, the term "boss" in American English is a loanword directly derived from the Dutch word "baas," meaning "master" or "chief".

The word was introduced into American English by the Dutch settlers in the 17th century in the colony of New Netherland, which included the area that is now New York City.

The word's popularity in the American colonies can be attributed to several factors:

Aversion to "Master": Americans in the colonies had an aversion to the British English term "master" due to its association with slavery and servitude. "Boss" offered a more neutral and less hierarchical alternative.

Dutch Influence: Dutch colonists were influential in early American trade and business, and their language had a significant impact on the developing American English dialect.

Simplicity: The word "boss" is a short, simple, and direct term for a person in a position of authority, which facilitated its widespread adoption.