"If you can possibly spare a division of cavalry, send them through Loudoun County to destroy and carry off the crops, animals, negroes, and all men under fifty years of age capable of bearing arms. In this way you will get many of Mosby's men. All male citizens under fifty can fairly be held as prisoners of war, and not as citizen prisoners. If not already soldiers, they will be made so the moment the rebel army gets hold of them." Sheridan straightway ordered all the cavalry of the Eighth Illinois, then the best regiment of its kind in the Army of the Potomac, to concentrate at Muddy Branch, preparatory to beginning operations against Mosby in Loudoun County. In his orders to General Auger he told that officer to exterminate as many as he could of "Mosby's gang." The command broke camp at Muddy Branch August 20, and crossed the Potomac with 650 men, the special object of the scout being, as stated in orders to Major Waite, "to break up and exterminate any bands or parties of Mosby's, White's, or other guerillas which may be met." Viewed in the light of a communication from Sheridan to Halleck, dated November 26, 1864, this expedition seems not to have been even moderately successful. In it he said: "I will soon commence work on Mosby. Heretofore I have made no attempt to break him up, as I would have employed ten men to his one, and for the reason that I have made a scape-goat of him for the destruction of private rights. Now there is going to be an intense hatred of him in that portion of this Valley, which is nearly a desert. I will soon commence on Loudoun County, and let them know there is a God in Israel...." In his determination to rid himself of his troublesome enemy, Sheridan, the next day, issued the following orders to Major-General Merritt, commanding the First Cavalry Division: