In this book Camp and Prison Journal by Griffin Frost, someone who served under Priest in 1861-'62 through the siege of Corinth and beyond, it says around mid-January 1862 on page 5 that says "Had an election for Lieut. Col. 1st Bat., 2nd Div. MSG. Capt. Priest was chosen." It says on page 9 that on 17 May "Col. Priest ordered to report himself and men, minus 160, at headquarters immediately; Cos. "A", "B" and "C" left to guard the bridge" which was a bridge about 10 miles south of Corinth on the Mobile & Ohio R.R. line. In reading through this soldier's account of service with Priest through the retreat from Corinth and beyond, to encamping at Tupelo, this fellow never mentions the battalion being converted to a regiment with the addition of more companies or anything of the sort. He mentions other much less important things like a raid on 14 May which captured 50 or 60 head of beef cattle from the federals but nothing about amalgamating Priest's command with another battalion to form a regiment or anything like that, something that one would think he would have certainly mentioned. Which leads me to believe that at the time of the siege of Corinth Lieut. Col. Priest was commanding his battalion (the 5th Missouri Infantry Battalion?) but not a regiment.