Here's how Arhoolie came into being, according to Arhoolie Founder and Field Recorder Extraordinaire, Chris Strachwitz:

Origins of the Names

I had thought of names like Delta, Gulf, Down Home, etc., for my label when Mack suddenly suggested ARWHOOLIE! My initial response was: "AR what?" But soon the name, at least a part of which apparently means a field holler, seemed rather appropriate for the music I wanted to record. The word, spelled as above by the recordist, appeared on a Library of Congress recording made in Mississippi and apparently was the response of the singer when asked what he called the selection just recorded. I have since heard the word "hoolie" in reference to a field holler but I think the "ar" in front of it was simply the man stuttering a bit in Mississippi fashion when somewhat nervous!

Chris Strachwitz

That's from:Arhoolie Records/History and there's some pretty interesting reading there if you like this sorta thing.

I've been a fan of Arhoolie Records works since I was 16 when I bought a double set called "The Roots of Americas Music."
I got a boxed set of the fortieth anniversary edition for myself this last Christmas and it is probably the definitive collection of American Vernacular Music. Chris Strachwitz went way beyond where Lomax left off.