See, here we differ. For instance, the core of progressivism is no longer confined to NE of Mason-Dixon even to the extent that it ever was ... indeed the looniest strongholds are now out West ... so making it about that seems to serve no function. Likewise carpet bagging as known from after tWBtS is itself a newer thing than there being Damn Yankees.
I’m not sure exactly when Damn Yankee became a subtype. It seems to me to have likely originally been used of big city Yankees in an arc from Boston to Philadelphia, with its heart firmly in money grubbing New York City, then expanded quickly to include more of lower New England, of Pennsylvania, and of New Jersey as industrialization progressed.
Actually, per family lore that phrase started shortly after the War Between the States:0)