I’d believe he was left at Wauhatchie
Private William T. McMillan Co. K 44th Mississippi (Blythe's Regiment) Captain W. L. Huff, left sick on the march from Taylor’s Store/Bridgeport, Ala., Aug. 22*,1863 by order Brig. Surgeon
* A couple of cards in his file record Aug. 23
August 21.— Left Shellmound.
August 22.— Arrived at Wauhatchie Station on the Nashville and Chattanooga Railroad. Distance, twenty-two miles.
August 23.— Moved back to Whiteside's Station on the Nashville and Chattanooga Railroad. Distance, eight miles.
Left Whiteside's Station for Chattanooga.