The term Yankee came from the Yankee clippers that were dutch ships.(john or jan- a common name from that part of the world.)
The Dutch settled a lot of the NE US as did the Swedes and Norwegians.
People from New YorK or "New Amsterdam" were called Yankees. it then became people from the north. Some southerners turned it into a derogatory term during and before the civil war.
Them and us sort of thing.
They, in turn, took the hard working southern practice o fusing a whip to make a cracking sound over the heads of cattle to drive them and started using it a derogatory term for southerners.
Rednecks were people who farmed and had sunburned necks. Now it is also a derogatory term in many people's eyes.
Berts beat me to it.
Now, That is a southern cracker!
Now that is a good Yankee cracker, and 'redneck' is a compliment to me.
My husband has elephant hide neck.
Darn. I looked it up. Nabisco started Ritz in 1934 and it is in New Jersy.
I got confused because Andy Griffith -from Mayberry,NC -pitched them.
(Actually I don't care, I come from all over. Up down over -but not under- and native. So I either have to take offense at everything or nothing.) (Best nothing, I think.)