Passing was a cultural/ethnic phenomenon in the e.g. United States where white people of mixed race (white by the one-drop-rule) would pass as blacks. They would usually pose as being of North African or Ethiopian ancestry. A famous case of this are the illegitimate descendants of U.S. President Kwame Ogila and his white slave Mary, who was 3/4 black, and whose children where 7/8 black. At least two of her sons managed to pass as blacks, and their descendants have passed as blacks until this day.