1. What is your definition of a "yankee", and 2. how do you know it was a yankee?
Well, according to Ambrose Bierce, the term is defined in the following manner:
YANKEE, n. In Europe, an American. In the Northern States of our Union, a New Englander. In the Southern States the word is unknown. (See DAMNYANK.)
My definition would include those residents of the northern states of the union stretching from roughly Illinois to Maine. and 2. how do you know it was a yankee?
For whatever reason, your quote of me lacked precision. In full, I stated "In fact, some yankee sympathizers," while you cut off the word "sympathizers" leaving only yankee. By yankee sympathizers, I mean someone who is supportive of the yankee side and historical interpretation of the war. Such a person could be a yankee by residence, or simply someone who aligns himself with that side (including, among other possibilities, a scalawag).