During the entire campaign I had been annoyed by guerrilla bands under such partisan chiefs as Mosby, White, Gilmore, McNeil, and others, and this had considerably depleted my line-of-battle strength, necessitating as it did large, escorts for my supply-trains.  The most redoubtable of these leaders was Mosby, whose force was made up from the country around Upperville, east of the Blue Ridge, to which section he always fled for a hiding-place when he scented danger.  I had not directed any special operations against these partisans while the campaign was active, but as Mosby’s men had lately killed, within my lines, my chief quartermaster, Colonel Tolles, and Medical Inspector Ohlenchlager, I concluded to devote particular attention to these “irregulars” during the lull that now occurred; so on the 28th of November, I directed General Merritt to march to the Loudoun Valley and operate against Mosby, taking care to clear the country of forage and subsistence, so as to prevent the guerrillas from being harbored there in the future their destruction or capture being well-nigh impossible, on account of their intimate knowledge of the mountain region.  Merritt carried out his instructions with his usual sagacity and thoroughness, sweeping widely over each side of his general line of march with flankers, who burned the grain and brought in large herds of cattle, hogs and sheep, which were issued to the troops.

While Merritt was engaged in this service the Baltimore and Ohio railroad once more received the attention of the enemy; Rosser, with two brigades of cavalry, crossing the Great North Mountain, capturing the post of New Creek, with about five hundred prisoners and seven guns, destroying all the supplies of the garrison, and breaking up the railroad track.  This slight success of the Confederates in West Virginia, and the intelligence that they were contemplating further raids in that section, led me to send, Crook there with one division, his other troops going to City Point; and, I hoped that all the threatened places would thus be sufficiently protected, but negligence at Beverly resulted in the capture of that station by Rosser on the 11th of January.

In the meanwhile, Early established himself with Wharton’s division at Staunton in winter quarters, posting his cavalry in that neighborhood also, except a detachment at New Market, and another small one at the signal-station on Three Top Mountain.  The winter was a most severe one, snow falling frequently to the depth of several inches, and the mercury often sinking below zero.  The rigor of the season was very much against the success of any mounted operations, but General Grant being very desirous to have the railroads broken up about Gordonsville and Charlottesville, on the 19th of December I started the cavalry out for that purpose, Torbert, with Merritt and Powell, marching through Chester Gap, while Custer moved toward Staunton to make a demonstration in Torbert’s