The New Student's Reference Work/Yankee

Yan'kee, the popular name for a New Englander in America, and in Europe often applied indiscriminately to the entire population of the United States, perhaps originated as a corruption of the word English or of French Anglais, as pronounced by the Indians — Yenghies, Yanghies, Yankees. It seems to have been first applied by British soldiers to the New Englanders as a term of reproach during the Revolutionary war. During the Civil War it was applied by the southern people to all the inhabitants of the northern states.