The way I read this Col. Joe Shelby was never captured at Prairie Grove. He and his staff was surrounded by about seventy-five federal cavalry about 2 miles northeast of Prairie Grove at a little spot in the road named Walnut Grove. He was given five minutes to surrender. While he was making up his mind on what to do, in rode Frank James and a bunch of Quantrill's men and put the Federal cavalry in disarray, saving Shelby from capture. Joe Shelby always held Frank James in high regard after that day. General Shelby long after the war showed up drunk at Frank James's trial as a character witness for Frank. He rambled on for hours about what a great man Frank James was. We had this discussion a few months ago on the Arkansas or Missouri message board, but I can't seem to find it now.
I had thought this affair had taken place at Hogeye, Arkansas four miles southwest of Prairie Grove, but the correct location was the little village of Walnut Grove, Arkansas.