ManifestTruth wrote:The term "cracker" is very old, comes from slavery times. Back then,
folks used the term to refer to brutal slaveowners who stayed cracking that whip across the back of enslaved blacks, hence the term "whip-cracker". It later got shortened to just "cracker". As blacks migrated from the South to other parts of the country, the term followed.
It was actually started by whites to refer to lower class whites
The Florida Cracker Trail is a route posted across southern Florida by the Florida Department of Transportation.
The October 27, 1863 Battle of Brown's Ferry, in the American Civil War, opened the so-called "Cracker Line". 
Crackin' Good Snacks (a division of Winn Dixie, a Southern grocery chain) has sold crackers similar to Ritz crackers under the name "Georgia Crackers". They sometimes came in a red tin with a picture of The Crescent, an antebellum plantation house in Valdosta, Georgia.
Before the Milwaukee Braves baseball team moved to Atlanta, Georgia, the Atlanta minor league baseball team was known as the "Atlanta Crackers". The team existed under this name from 1901 until 1965. They were members of the Southern Association from their inception until 1961, and members of the International League from 1961 until they were moved to Richmond, Virginia in 1965. However, it is suggested the name was derived from players "cracking" the baseball bat and this origin makes sense when considering the Atlanta Negro League Baseball team was known as the "Atlanta Black Crackers".
In John Boorman's 1972 film Deliverance, Lewis, played by Burt Reynolds, derisively refers to the rural people they encounter as being "crackers", implying that they were slow-witted hillbillies who lived in a world much different from that of him and his friends from a southern city.
In the 2000 film O Brother Where Art Thou?, the upper class white character "Pappy" O'Daniel, candidate for the Governor of Mississippi and sponsor of the radio show Flour Hour, meets a lower class and uneducated white character as he arrives at the radio station for his program. Pappy is told that he can make $10 for singing into a can inside, whereupon he snaps, "I'm not here to make a record, you dumb cracker."