Furthermore, Mosby and other partisans in Loudoun routinely raided Union garrisons in Fairfax County and along the Potomac River in Maryland.

In order to limit this threat, General Grant wrote to Sheridan on August 16 suggesting: If you can possibly spare a division of Cavalry, send them through Loudoun County and destroy and carry off all the crops, animals, negroes, and all men under fifty years of age capable of bearing arms.

[2] Though Sheridan had by then defeated Early's army in late October at the Battle of Cedar Creek, he feared such action might agitate anti-war advocates and negatively impact the reelection of Abraham Lincoln.

In late November, with Lincoln's reelection assured, Sheridan decided he could finally safely conduct operations against Mosby.

[3] The following day he ordered Major General Wesley Merritt and his 1st Cavalry Division to Loudoun: You are hereby directed to proceed, to-morrow morning at 7 o'clock, with the two brigades of your division now in camp, to the east side of the Blue Ridge, via Ashby's Gap, and operate against the guerrillas in the district of country bounded on the south by the line of the Manassas Gap Railroad as far east as White Plains, on the east by the Bull Run Range, on the west by the Shenandoah River, and on the north by the Potomac... To clear the country of these parties that are bringing destruction upon the innocent, as well as their guilty supporters, by their cowardly acts, you will consume and destroy all forage and subsistence, burn all barns and mills and their contents, and drive off all livestock in the region, the boundaries of which are described above.

This order must be literally executed, bearing in mind, however, that no dwellings are to be burned and that no personal violence be offered the citizens...[4] On the morning of the 28th, Merritt's 1st Cavalry Division set out for Ashby's Gap in the Blue Ridge and by midday had crossed the mountain and arrived at Paris.

Instead the Rangers attempted to help local farmers by driving off their livestock ahead of the Federal columns, often bringing them into areas already put to the torch.

In the words of Charles Humphreys, who was with the reserve brigade: Some idea of the general destruction may be formed when I relate that in one day two regiments of our brigade burned more than one hundred and fifty barns, a thousand stacks of hay, and six flour mills, besides having driven off fifty horses and three hundred head of cattle.

This was the most unpleasant task we were ever compelled to undertake...[5] It was heart-piercing to hear the shrieks of women and children, and to see even men crying and beating their breasts, supplicating for mercy on bended knees, begging that at least one cow - an only support - might be left.