Writing in the New Yorker in April 1986, Calvin Trillin told the story of Susie Guillory, a native of Louisiana who, when applying for a passport, discovered that she was African American. According to the state's 'one-drop rule', Americans with even a 1 in 32 part of Negro blood - or a nameless, faceless great-great-great-grandfather - were classified as 'Col', or coloured, on birth certificates. When he learned of the discovery, Guillory's husband said: 'Hell, she ain't a nigger.' The one-drop rule was phased out soon afterwards, partly as a result of the legal suit brought by Guillory, but it persists in common parlance, in both the US and Britain: your part-Scottish, part-Native American, part-Spanish friend is often 'black' if there is a hint of Africa in his or her make-up.

LRB 5 October 2006 | PDF Download