No, that's where black people started using it about white people.
I'd be interested in your basis for that.
I do not think that whites using whips on blacks was a common occurrence - enlighten me if I am wrong.
That it occurred is irrefutable, but was in prevalent enough for it to become a common pejorative for white masters. I think that came about as a recent interpretation of what went on during the slave era.
So, it may well be in reference to some made up revisionist history of what 'cracker' meant, but I don't think it has basis in actual fact. It is a modern affectation, picked up for the reason that it can re-ignite the slave era emotions.
White people from Florida were called crackers by other whites - pejorative in the sense that they were uneducated - old time version of 'redneck.'
I have not researched this - it is based on what I have read over the years.
If you can substantiate that 'cracker' was used by the slaves of the slave era to talk about white people in general, then please enlighten me.
I want to know.