Lumper vs. Swamper: Which is Correct?

Have you ever driven past a warehouse with a bunch of semi-truck trailers attached to it? Those trailers need to be unloaded, right? In a lot of cases staffing companies (especially Diversified Staffing Services) would supply people to unload trailers, should the warehouse not have dedicated staff. The general labourers that are tasked to unload trailers go by a couple of different names, but nobody seems to know the correct one. One of the names which is ‘Swamper’ and the other is ‘Lumper’. They are both unusual words, but which one is correct?

Here is the origin and definition of ‘Swamper’ according to Wikipedia:

“A swamper in occupational slang is an assistant worker, helper, maintenance person, or someone who performs odd jobs. The term has its origins circa 1857 in the southern United States to refer to a workman who cleared roads for a timber faller in a swamp, according to the Oxford English Dictionary.”

Here is the definition and origin of ‘Lumper’ according to dictionary.com

“A day laborer employed to handle cargo, as fish or timber. This word is believed to of originated in 1775.”

How can we know for sure the absolute correct name? We may never know!