You are right about Edwards in his post war writings about Shelby, he speaks of the "iron ranks" and the "iron wall". Capt. Shelby's first enlistment expired June 10, 1862, He re-enlisted July 1, 1862 at DuValls Bluff, Arkansas and a short time later on July 28, 1862 he was promoted to Col., but I've still not found a contemporary use of the nickname "Iron Brigade" by Prairie Grove for Shelby's Brigade. It must have been a long drawn out affair for Shelby to accept and embrace the nickname Iron Brigade or more contemporaries would have been using it. For Shelby Brigade its almost like it was a post war popular term. Is there a contemporary "We are the Iron Brigade" source out there, someone should know and help us out.