I don't recall seeing a reference to a formal Second Corps around the time of Prairie Grove, except in Harrell's "Arkansas" volume of Confederate Military History. Basically, Harrell just listed the "troops not included in the First Army Corps", per Special Orders No. 39, under the heading "Second Corps," with no commanding officer listed. I've run across a handful of erroneous assumptions made by Harrell, and I think this is one of them.

As far as I can tell, it wasn't until long after Prairie Grove that a formal Second Corps came into being. There's a December 1864 return of troops in the Trans-Mississippi Department organized into four corps --

First Corps -- Buckner.
Second Corps -- Magruder.
Third Corps -- Walker.
Fourth Corps -- Price.