Gavin, I'm sorry I can't locate Milton A.Isaac.The 57IL. was in Army of Tenn.,Second Division, Third Brigade with the 7IL.Inf. and the 50IL.Inf.. My GGUncle was in the 7IL.Inf.. I have a copy of Ambose's History of the Regiment and it has a day by day account of the Brigade from Pittsburg Landing to Iuka. If you are interested.If Johnny Reb is correct perhaps this is when he was appointed Assistant Surgeon.Gov. Yates I know signed my GGGrandfathers commision.I recieved a copy through the IL.Sec.of State.You might research Army of Tenn. Sp.Field Orders and Sp.Orders around the date you think he was appointed.The Medical Dept. is a little different.
Wednesday,May 7th. To-day Governor Yates visits

the Seventh and makes them a speech, which is full

of cheer, full of hope and life, right straight from

Dick s big heart. He has come down to Tennessee

to look after the sick and wounded Illinois soldiers.

How fortunate it is for Illinois to have so good and

noble a governor, during this bloody war. This

afternoon our division has been reviewed; an impos

ing scene ; such a uniformity of motion and so much

virn convince the lookers on that the Second Division

cannot be surpassed in the army.