How did I not know that WASPS (PERSONS) was a Library of Congress subject heading. (Or did I? My mind is a sieve sometimes.) The record indicates that the heading was established (or last modified?) in 1986.
It is used for WHITE ANGLO-SAXON PROTESTANTS. Other cross references are:
British Americans
Ethnology United States
European Americans
Protestants United States
Whites
I found this when looking up a book Kate Haas recommended, Cheerful money : me, my family, and the last days of Wasp splendor.
There are two other entries in LC for WASPS (PERSONS)--BIOGRAPHY, eight entries for WASPS (PERSONS)--FICTION and three for --HUMOR.
Good stuff!