Partain is most likely of French origin, and my family too has a predominace of old french christian names. They seem to have settled in the old French colony, which spread from Alabama to slightly wesk of Arkansas.
Our family story involves bee/honey hunting amongst other trapping occupations, which all jives with a French ancestor, maybe connected with Cherokees, and those were allies in the French and Indian war in the same area.
It might be from South West France, where it might be related to the surname "Petain", which is pronounced in French with an "ehr" sound to the first half. The surname might also have originally ended with a gne, as in partainge, the same way that they spell mountains...another alternative is that is a corruption of de la Fountaine, in that American born descendants may not have been as careful to preserve the spelling.
There is a likely second chance that Partains were French protestants via northern Scotland, like the Jardines, who first fled to ally Soctland and then to America.
While many propose that Partain is the same as Parton, and indeed certain folks might have crossed that border unwittingly, I believe that line of thought to be a false cognate for my family.Parton is a well established Anglo/Scot name, Parten is a clear German name, and Partin is a clear misspelling of Parton.The olde english claim to Pear Farmer doesn't really hold.Similar games can be played with other names, like Jordan, which also have multiple origins, like (Jardines, an anglo version of Zigeuner, a returnee from the Crusades, someone who lived near a river, a moorish surname, the list goes on..the American spelling is the same, but very different roots).
I wonder if the original Partains were actually French to begin with, and might they have been Basque or other relocatee from the 30 year war?