...guarding that flank, bringing up the rear on the road via Greenwood to Willamsport, which was the route designated for the main portion of the wagon trains and ambulances, under the special charge of Brigadier-General Imboden , who had a mixed command of artillery, infantry and cavalry (his own). Previous to these instructions I had, at the instance of the Commanding-General, instructed Brigadier-General Robertson, who...