Why is Arkansas pronounced Ar-kan- SAW?
Dear Straight Dope:
Why on Earth is Arkansas pronounced "ark-an-SAW"?
Because, unlike other states (Illinwaw, for instance), the original French pronunciation stuck.
Of course, as native Kansans will tell you, "Arkansas" is pronounced ahr-KAN-suz.
Seriously, Arkansas is a French variant of the Siouxian word Quapaw (also a tribe located in the area around the area where Kansas, Missouri, Oklahoma, and Arkansas almost meet, and, additionally, a town in northeastern Oklahoma, between Miami and Baxter Springs, Kansas). Quapaw means, literally, "downstream people."
How the French got "Arkinsaw" from "Quapaw," on the other hand, is a mystery to us.