The American Heritage Dictionary (3d ed., 1992) in a word history note describes "Yankee" as "an excellent example of a widely known word about whose origins cannot be determined." They opt for it being a nickname from the Dutch Janke (Jan/John), used derisively by the British in the the 18th century for New Englander. H. L. Mencken in "The American Language - Supplement One"(1945) opts for Jan kees (John Cheese), but has an extended discussion of other derivations (pp. 192-96). Natalie Naylor, Hofstra University