The term originally characterized farmers that had a red neck, caused by sunburn from long hours working in the fields. A citation from 1893 provides a definition as “poorer inhabitants of the rural districts … men who work in the field, as a matter of course, generally have their skin stained red and burnt by the sun, and especially is this true of the back of their necks”.[12] Hats were usually worn and they protected that wearer’s head from the sun, but also provided psychological protection by shading the face from close scrutiny.[13] The back of the neck however was more exposed to the sun and allowed closer scrutiny about the person’s background in the same way callused working hands could not be easily covered.
By 1900, “rednecks” was in common use to designate the political factions inside the Democratic Party comprising poor white farmers in the South.[14] The same group was also often called the “wool hat boys” (for they opposed the rich men, who wore expensive silk hats). A newspaper notice in Mississippi in August 1891 called on rednecks to rally at the polls at the upcoming primary election:[15]
I mean to have an actual citation from 1893 that provides a written out definition is huge. These things are around for a good bit before making their way into documentation.
Reading through the talk, many people say coal and then provide links that come far after 1893.
The Wikipedia article doesn’t link to a 1893 citation. It links for a single paywalled article to make that claim. This sounds like an urban legend loop that seems to make sense until examined.