Blacks were expected to refer to white males in positions of authority as "Boss" or "Cap'n"--a title of respect that replaced "Master" or "Marster" used in slave times. All black men, on the other hand, were called by their first names or were referred to as "Boy," "Uncle," and "Old Man"--regardless of their age. https://files.nc.gov/dncr-moh/jim%20crow%20etiquette.pdf