Where did the term "Yankee" come from when referring to an American?

The colonists were known as yankees, initially only those from New Amsterdam, but it soon spread to ALL the colonists. From the revolutionary war onwards Americans have been known as Yanks: the civil war distinction is important to Americans, but not to those outside the country

The origin of the term "Yankee" is not certain but was certainly a reference, in the southern states, to northern Americans. It was first used around 1683 and was used insultingly to reference Dutch settlers in New York (New Amsterdam then.) Thoughts are it may be a bastardization of Janke, litteraly Little John, a nickname for a common Dutch name Jan. The Dutch pronounce the "J" as a "Y."

During the first and second world wars, mostly in the second, the world took to calling Americans "Yankees." I have no idea why but they did. So most of the world still thinks of Americans as Yankees. Go figure.

The Yankees were people who were trading in the Triangle Trade before the Revolution.

Civil War or Revolutionary War, I think

Yankee doodle dandy!