where did the word redneck originate from?

I believe it was laborers that started it. Their necks got sun burned. Yes only white people can be called rednecks. It's like saying trailer trash.

The origins of the term redneck actually go back to the 1930's in a number of disputes in West Virginia. A large group of unionized miners marched south to Logan County, to pressure the mine owners there to allow their miners to become unionized. To identify themselves, the miners all wore red bandannas around their necks. The publicity associated with the battles and the subsequent court cases created the term red-necks, and at that time they were viewed as the good guys in the conflict.

Originally, the term came from the later 1800's in southern Georgia and Alabama to refer to sharecroppers who worked in the fields thus getting a sunburned neck. They were called 'rednecks' as a term meant for hard working people. Today, the term is used by comedians and commentators to refer to people who are uneducated, close-minded and racist individuals.

redneck

"cracker," 1893; attested 1830 in more specialized sense ("This may be ascribed to the Red Necks, a name bestowed upon the Presbyterians in Fayetteville," from Ann Royall, "Southern Tour I," p.148). According to various theories, red perhaps from anger, or from pellagra, but most likely from mule farmers' outdoors labor in the sun, wearing a shirt and straw hat, with the neck exposed.

Another reference

The word redneck was first cited in Scotland. In Scotland, the National Covenant and The Solemn League and Covenant (a.k.a. Covenanters) signed documents stating that Scotland desired a Presbyterian Church Government, and rejected the Church of England as their official church. Many of the Covenanters signed these documents using their own blood, and many in the movement began wearing red pieces of cloth around their neck to signify their position to the public. They were referred to as Rednecks. These Scottish Presbyterians migrated from their lowland Scottish home to Ulster (the northern province of Ireland) during the 17th Century and soon settled in considerable numbers in North America across the 18th Century. Some immigrated directly from Scotland to the American colonies in the late 18th and early 19th-centuries as a result of the Lowland Clearances. One etymological theory holds that since many Scots-Irish Americans who settled in Appalachia and the South were Presbyterian, the term was bestowed upon them and their descendants.

Redneck - Possible American Etymology

The popular etymology says that the term derives from such individuals having a red neck caused by working outdoors in the sunlight over the course of their lifetime. The effect of decades of direct sunlight on the exposed skin of the back of the neck not only reddens fair skin, but renders it leathery and tough, and typically very wrinkled and spotted by late middle age. Similarly, some historians claim that the term redneck originated in 17th-Century Virginia, because indentured servants were sunburnt while tending plantation crops.

Redneck is a historically derogatory slang term used in reference to poor white farmers in the Southern United States. It is similar in meaning to cracker (especially regarding Georgia and Florida), hillbilly (especially regarding Appalachia and the Ozarks) and white trash.