I read that the term Yankee derives from the time when the British were battling the Dutch for North America (the first name for New York was New Amsterdam) and they called the folks from that area as Jan Keese.
My father almost passed out when I called someone a “Jerk” as a young woman. It never occurred to me that the term had a rather unsavory history. I stared in disbelief as he lectured me on his disappointment that the finishing school for which he paid a rather handsome price had failed to produce a young lady. Thank God he's in a better place today or he'd definitely be on his way.