one-drop rule

Noun

the one-drop rule

1. (US) The notion that one drop of black blood (i.e., any African ancestry at all) makes a person black.
   • [T]he notorious historian William Estabrook Chancellor […] helped assemble a controversial biographical portrait accusing President Warren Harding of covering up his family’s “colored” past. […] Under the one-drop rule of American race relations, Chancellor claimed, the country had inadvertently...2008 April 6, Beverly Gage, “Our First Black President?”, in The New York Times, archived from the original on 19 Aug 2020, retrieved 08 Jan 2017
   • It was the wadjelas that created the ‘one drop’ rule, that defined anybody with a single bla(c)k ancestor as black. They did that to separate people, to create a caste system, to protect the notion of whiteness, to protect whiteness from the merest ‘impurity’, from the merest influx of colour.2021 November 7, Claire [G.] Coleman, “Not quite blak enough: ‘The people who think I am too white to be Aboriginal are all white’”, in The Guardian, archived from the original on 03 Dec 2021