Many etymologies have been proposed for Yankee , but its origin is still uncertain. What we do know is that in its earliest recorded use Yankee was a pejorative term for American colonials used by the British military. The first evidence we have is in a letter written in 1758 by British General James Wolfe, who had a very low opinion of the New England troops assigned to him. We also have a report of British troops using the term to abuse citizens of Boston. In 1775, however, after the battles of Lexington and Concord had shown the colonials that they could stand up to British regulars, Yankee became suddenly respectable and the colonials adopted the British pejorative in defiance. Ever since then, a derisive and a respectable use of Yankee have existed side by side.
Traditionally, Yankee was most often used to refer to a New Englander descended from the original settlers of the region (thus often suggesting Puritanism and thrifty values).  By the mid-20th century, some speakers applied the word to any American born north of the Mason–Dixon Line , though usually with a specific focus still on New England. New England Yankee might be used to differentiate.  However, within New England itself, the term still refers more specifically to old-stock New Englanders of English descent. For example: