The term Hillbilly originated from the Scotch-Irish term for the "supporters of King William." It combines the words "Hill" (Denoting the location; the hills and mountains of Appalachia) and Billy. The word "Billy" derived from "Billy Boys.” The Billy Boys were Scotch-Irish immigrants that settled the hill-country of Appalachia and brought with them their songs and ballads that dealt with William, Prince of Orange, who defeated the Catholic King James II of the Stuart family at the Battle of the Boyne, Ireland in 1690.
Other simple terms are also used to describe Hillbillies, they include; Mountain Folk, Ridgers, Hill people, People of the Mountains, Cloud Hoppers [Clod Hoppers are farmers], Hicks, Backwoods Folk, Yokel, Bumpkin, Chawbacon, Rube, Hayseed, Cornball, Boors, Mountaineer, Churl. Not all of those are flattering.
Redneck; The origins of this term as is with the language can be traced to the Scottish and refer to supporters of the National Covenant and The Solemn League and Covenant, or "Covenanters." They were largely Lowland Presbyterians, many of whom would flee Scotland for Ulster (Northern Ireland) during persecutions by the British Crown. The Covenanters of 1638 and 1641, signed the documents that stated that Scotland desired the Presbyterian form of church government, and would not accept the Church of England as its official state church. Many Covenanters signed in their own blood, and wore red pieces of cloth around their necks as distinctive insignia; hence the term "Red neck," (rednecks) became slang for a Scottish dissenter.
As they migrated to the Appalachia region, the term followed them. It was between 1912-1936 when coal miners began to wear red handkerchiefs around their necks as a part of their informal uniforms. Came to be recognized as a sign of solidarity or “union men” or “strikers.” The use of redneck to designate "a union member" was especially popular during the 1920s and 1930s in the coal-producing regions of southern West Virginia, eastern Kentucky, and western Pennsylvania, where the word came to be specifically applied to a miner who belonged to a union.
Today, the term is used to describe everything from Southerners to anyone living in a rural community. To others, this term conjures images of hard-working blue-collar, bel esprit, obstreperous men and women.
Most people think hillbillies and rednecks are the same. They are not. You can be a redneck anywhere you want to be. But hillbillies always come from the mountains and hills. Hillbillies also hold tight to the old ways and traditions handed down to them. Hillbillies also speak the language of the mountains; Mountain Dialect.
They do share common traits, such as being rowdy and mean, but they hold to the Old South traditions and customs. [No that doesn't mean racism] Old South ways are the morals and ethics of being a Southern Gentleman or Lady.