The book reference is " A History of the Third Missouri Cavalry" by A.W.M. Petty, published Little Rock: J Wm. Demby 1865.
I understand the the 3rd Cav Missouri State Militia U.S.is not the same as the 3rd MO Cav. U.S.. There seems to be quite a bit of info on MSM in GENFORUM.
General Benjamin M.Prentiss was at Shiloh but no reference to the 3rd Cav. being there. Thanks.