According to the tour guides in St.Augustine, the term "cracker" came from the early settlers who were cattle farmers. They used a lightweight sort of bullwhip to drive the cattle by making it "crack" in the air behind the cattle. They didn't actually whip the cows, just used the noise as a controlling and driving device. The term "cracker", of course, referred to the cattle drivers who "cracked" the whips. The term has evolved to mean someone who was born & raised here.

Don't know if that's 100% correct, but that's what they told us...