- cracker (n.1)
- mid-15c., "hard wafer," but the specific application to a thin, crisp biscuit is 1739; agent noun from crack (v.). Cracker-barrel (adj.) "emblematic of down-home ways and views" is from 1877.
- cracker (n.2)
- Southern U.S. derogatory term for "poor, white trash" (1766), probably from mid-15c. crack "to boast" (e.g. not what it's cracked up to be), originally a Scottish word. Cf. Latin crepare "to rattle, crack, creak," with a secondary figurative sense of "boast of, prattle, make ado about."
I should explain to your Lordship what is meant by crackers; a name they have got from being great boasters; they are a lawless set of rascalls on the frontiers of Virginia, Maryland, the Carolinas and Georgia, who often change their places of abode. [1766, G. Cochrane]
But DARE compares corn-cracker "poor white farmer" (1835, U.S. Midwest colloquial). Especially of Georgians by 1808, though often extended to residents of northern Florida. Another name in mid-19c. use was sand-hiller "poor white in Georgia or South Carolina."