I remained at Monocacy until General Sheridan arrived, on the morning of the 6th, and, after a conference with him in relation to military affairs in that vicinity, I returned to City Point by way of Washington.
On the 7th of August, the Middle Department, and the Departments of West Virginia, Washington, and Susquehanna, were constituted into the "Middle Military Division," and Major-General Sheridan was assigned to temporary command of the same.
Two divisions of cavalry, commanded by Generals Torbert and Wilson, were sent to Sheridan from the Army of the Potomac.

The first reached him at Harper's Ferry about the 11th of August.
His operations during the month of August and the fore part of September were both of an offensive and defensive character, resulting in many severe skirmishes, principally by the cavalry, in which we were generally successful, but no general engagement took place.

The two armies lay in such a position--the enemy on the west bank of the Opequon Creek covering Winchester, and our forces in front of Berryville--that either could bring on a battle at any time.

Defeat to us would lay open to the enemy the States of Maryland and Pennsylvania for long distances before another army could be interposed to check him.

Under these circumstances I hesitated about allowing the initiative to be taken.
Finally, the use of the Baltimore and Ohio Railroad, and the Chesapeake and Ohio Canal, which were both obstructed by the enemy, became so indispensably necessary to us, and the importance of relieving Pennsylvania and Maryland from continuously threatened invasion so great, that I determined the risk should be taken.