I see that it is time, again, to educate some of you'all on a neglected part of American history.
The term originated in Scotland when Scots were in one of their many battles with the English - this one over religion. The English were trying to force the Episcopalian Church of England on the Scots, and they weren't having any of it. A red cloth worn around the neck was the sign of an anti-episcopalian.
Some of the Scots wound up in the Ulster Plantation, they were known as the Ulster Scots in Ireland, many of whom got tired of warring with both the English and the Irish and came to America in the very early 18th century. There, they were originally just called Irish, but when the real Irish started showing up about a century and a half later, the Scots-Irish took pains to make clear the difference between the two groups.
The English Colonial establishment neither like nor trusted the Scots-Irish but appreciated their warrior nature. Leaders like Cotton Mather invited them to live along the border to secure the frontier. It fit the bill because all of the land along the coast was too expensive and already settled, and after centuries of fighting the English, Irish, each other and whoever else came along, border fighting with Indians and French would just be a change of opponent and scenery.
The Scots-Irish were independent, isolationist, incredibly stubborn and distrusting of any centralized authority. Although they settled in many places in America (including Maine and New Hampshire), they were used to moving frequently and seizing and clearing land. Many of them wound up in the rugged Allegheny Mountains and similar areas in Virginia, Georgia, Tennessee, Kentucky, and the Carolinas. They became the original Hillbillies, a term which is believed to have originated in Scotland and Ireland.
As time went by the Scots-Irish tended to stay to themselves in the hills, where they lead a tough life. Redneck, Hillbilly, and Cracker were all terms used to describe them. Cracker, by the way, did not come from the term for cracking bullwhips, or cracking corn. While the Scots-Irish had always been called names like Redneck, the names began to spread to all poor whites in the South after the War of Northern Aggression. The Yankees subjected the South to great economic deprivation and many families and communities fell into a state of poverty that lasted for decades. There was a rejection of the whole class of poor southern whites. Eventually names like Redneck, Cracker, White-Trash and Peckerwood came to be applied to anybody that was a poor white Southerner.
Eventually the people, just like any rejected underclass, became the object of ridicule. The terms to describe them, and the image that those terms brought to mind, became derogatory when used by outsiders.
I have been called, and have called many others, Redneck, Cracker, White-Trash, Peckerwood, etc. The way in which it is used, and who is using it, dictate the reaction. Said under one set of circumstances it is just friendly banter. Said under a different set of circumstances, it is, as we Rednecks say, time for somebody to get an ass whupping.
As for Murtha. The most polite thing I can think of to say about the man is that he as a senile old windbag who runs off at the mouth without much thought.
Haditha Marine prepares to sue Murtha over smear